diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..589e214
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "server/php/example/httpserver"]
+	path = server/php/example/httpserver
+	url = git://github.com/youngj/httpserver.git
diff --git a/res/menu/mainmenu.xml b/res/menu/mainmenu.xml
index 4c3ea24..cc7148d 100755
--- a/res/menu/mainmenu.xml
+++ b/res/menu/mainmenu.xml
@@ -6,4 +6,7 @@
     <item android:id="@+id/test"          
             android:icon="@drawable/icon"
           android:title="@string/test" />
+    <item android:id="@+id/check_now"          
+            android:icon="@drawable/icon"
+          android:title="@string/check_now" />          
 </menu>
\ No newline at end of file
diff --git a/res/values/strings.xml b/res/values/strings.xml
index b3b6094..8dc1820 100755
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -3,4 +3,5 @@
     <string name="app_name">KalSMS 2</string>
     <string name="settings">Settings</string>
     <string name="test">Test</string>
+    <string name="check_now">Check Now</string>
 </resources>
diff --git a/server/php/KalSMS.php b/server/php/KalSMS.php
new file mode 100755
index 0000000..3c9a39d
--- /dev/null
+++ b/server/php/KalSMS.php
@@ -0,0 +1,177 @@
+<?php
+
+/*
+ * PHP server library for KalSMS
+ *
+ * For example usage see example/www/index.php
+ */
+
+class KalSMS
+{
+    const ACTION_INCOMING = 'incoming';
+    const ACTION_OUTGOING = 'outgoing';
+    const ACTION_SEND_STATUS = 'send_status';
+    const ACTION_TEST = 'test';
+
+    const STATUS_QUEUED = 1;
+    const STATUS_FAILED = 2;
+    const STATUS_SENT = 3;
+    
+    static function new_from_request()
+    {
+        $version = @$_SERVER['HTTP_X_KALSMS_VERSION'];        
+    
+        return new KalSMS();
+    }    
+    
+    static function escape($val)
+    {
+        return htmlspecialchars($val, ENT_QUOTES, 'UTF-8');
+    }
+    
+    function get_request_action()
+    {
+        switch (@$_POST['action'])
+        {
+            case static::ACTION_INCOMING:
+                return new KalSMS_Action_Incoming($this);
+            case static::ACTION_OUTGOING:
+                return new KalSMS_Action_Outgoing($this);                
+            case static::ACTION_SEND_STATUS:
+                return new KalSMS_Action_SendStatus($this);
+            case static::ACTION_TEST:
+                return new KalSMS_Action_Test($this);
+            default:
+                return new KalSMS_Action($this);
+        }
+    }        
+    
+    function get_request_phone_number()
+    {
+        return @$_SERVER['HTTP_X_KALSMS_PHONENUMBER'];
+    }        
+    
+    function is_validated_request($correct_password)
+    {
+        $signature = @$_SERVER['HTTP_X_KALSMS_SIGNATURE'];        
+        if (!$signature)
+        {
+            return false;
+        }
+        
+        $is_secure = (!empty($_SERVER['HTTPS']) AND filter_var($_SERVER['HTTPS'], FILTER_VALIDATE_BOOLEAN));
+        $protocol = $is_secure ? 'https' : 'http';
+        $full_url = $protocol . "://" . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];    
+        
+        $correct_signature = $this->compute_signature($full_url, $_POST, $correct_password);           
+        
+        //error_log("Correct signature: '$correct_signature'");
+        
+        return $signature === $correct_signature;
+    }
+
+    function compute_signature($url, $data, $password)
+    {
+        ksort($data);
+        
+        $input = $url;
+        foreach($data as $key => $value)
+            $input .= ",$key=$value";
+
+        $input .= ",$password";
+        
+        //error_log("Signed data: '$input'");
+        
+        return base64_encode(sha1($input, true));            
+    }
+}
+
+class KalSMS_OutgoingMessage
+{
+    public $id = '';
+    public $to;
+    public $message;
+}
+
+class KalSMS_Action
+{
+    public $type;    
+    public $kalsms;
+    
+    function __construct($kalsms)
+    {
+        $this->kalsms = $kalsms;
+    }
+}
+
+class KalSMS_Action_Test extends KalSMS_Action
+{    
+    function __construct($kalsms)
+    {
+        parent::__construct($kalsms);
+        $this->type = KalSMS::ACTION_TEST;
+    }    
+}
+
+class KalSMS_Action_Incoming extends KalSMS_Action
+{    
+    public $from;
+    public $message;
+
+    function __construct($kalsms)
+    {
+        parent::__construct($kalsms);
+        $this->type = KalSMS::ACTION_INCOMING;
+        $this->from = $_POST['from'];
+        $this->message = $_POST['message'];
+    }
+    
+    function get_response_xml($messages)
+    {
+        ob_start();
+        echo "<?xml version='1.0' encoding='UTF-8'?>\n";
+        echo "<Response>";
+        foreach ($messages as $message)
+        {   
+            echo "<Sms id='".KalSMS::escape($message->id)."'>".KalSMS::escape($message->message)."</Sms>";
+        }
+        echo "</Response>";        
+        return ob_get_clean();
+    }
+}
+
+class KalSMS_Action_Outgoing extends KalSMS_Action
+{    
+    function __construct($kalsms)
+    {
+        parent::__construct($kalsms);
+        $this->type = KalSMS::ACTION_OUTGOING;
+    }
+    
+    function get_response_xml($messages)
+    {
+        ob_start();
+        echo "<?xml version='1.0' encoding='UTF-8'?>\n";
+        echo "<Messages>";
+        foreach ($messages as $message)
+        {   
+            echo "<Sms id='".KalSMS::escape($message->id)."' to='".KalSMS::escape($message->to)."'>".
+                KalSMS::escape($message->message)."</Sms>";
+        }
+        echo "</Messages>";        
+        return ob_get_clean();
+    }
+}
+
+class KalSMS_Action_SendStatus extends KalSMS_Action
+{    
+    public $status;
+    public $id;
+
+    function __construct($type)
+    {
+        $this->type = KalSMS::ACTION_SEND_STATUS;        
+        $this->status = (int)$_POST['status'];
+        $this->id = $_POST['id'];
+    } 
+}
\ No newline at end of file
diff --git a/server/php/README.txt b/server/php/README.txt
new file mode 100755
index 0000000..cabf434
--- /dev/null
+++ b/server/php/README.txt
@@ -0,0 +1,25 @@
+
+PHP server library for KalSMS, with example implementation
+
+The KalSMS.php library is intended to be used as part of a PHP application 
+running on an HTTP server that receives incoming SMS messages from, and sends 
+outgoing SMS messages to an Android phone running KalSMS.
+
+To run the example implementation, the example/www/ directory should be made available 
+via a web server running PHP (e.g. Apache). You can also use the included standalone 
+PHP web server, by running the following commands:
+    git submodule init
+    php server.php
+    
+example/config.php contains the list of phone numbers and passwords for phones running KalSMS.
+
+On a phone running KalSMS, go to Menu -> Settings and enter:
+    * Server URL: The URL to example/www/index.php. 
+        If you're using server.php, this will be http://<your_ip_address>:8002/
+    * Your phone number: One of the phone numbers listed in example/config.php
+    * Password: The corresponding password in example/config.php
+
+To send an outgoing SMS, use 
+    php example/send_sms.php
+
+See KalSMS.php and example/www/index.php 
\ No newline at end of file
diff --git a/server/php/example/config.php b/server/php/example/config.php
new file mode 100755
index 0000000..6a6cadf
--- /dev/null
+++ b/server/php/example/config.php
@@ -0,0 +1,9 @@
+<?php
+
+$PASSWORDS = array(
+    '16505551212' => 'rosebud',
+    '16505551213' => 's3krit',
+);
+$PHONE_NUMBERS = array_keys($PASSWORDS);
+
+$OUTGOING_DIR_NAME = __DIR__."/outgoing_sms";
\ No newline at end of file
diff --git a/server/php/example/httpserver b/server/php/example/httpserver
new file mode 160000
index 0000000..95a38ab
--- /dev/null
+++ b/server/php/example/httpserver
@@ -0,0 +1 @@
+Subproject commit 95a38ab08f14ac54dc64b6f6c008d7f69af8a8f4
diff --git a/server/php/example/send_sms.php b/server/php/example/send_sms.php
new file mode 100755
index 0000000..821f638
--- /dev/null
+++ b/server/php/example/send_sms.php
@@ -0,0 +1,41 @@
+<?php
+
+// invoke from command line 
+
+require_once __DIR__."/config.php";
+
+$arg_len = sizeof($argv);
+
+if ($arg_len == 4)
+{
+    $from = $argv[1];
+    $to = $argv[2];
+    $message = $argv[3];
+}
+else if ($arg_len == 3)
+{    
+    $from = $PHONE_NUMBERS[0];
+    $to = $argv[1];
+    $message = $argv[2];
+}
+else
+{
+    error_log("Usage: php send_sms.php [<from>] <to> \"<message>\"");
+    error_log("Examples: ");
+    error_log("     php send_sms.php 16505551212 16504449876 \"hello world\"");
+    error_log("     php send_sms.php 16504449876 \"hello world\"");
+    die;
+}
+
+$id = uniqid("");
+
+$filename = "$OUTGOING_DIR_NAME/$id.json";
+
+file_put_contents($filename, json_encode(array(
+    'from' => $from,
+    'to' => $to,
+    'message' => $message,
+    'id' => $id
+)));
+
+echo "Message $id added to outgoing queue\n";
\ No newline at end of file
diff --git a/server/php/example/server.php b/server/php/example/server.php
new file mode 100755
index 0000000..1eab65f
--- /dev/null
+++ b/server/php/example/server.php
@@ -0,0 +1,46 @@
+<?php
+
+/*
+ * Example standalone HTTP server that routes all .php URIs to PHP files under ./example_www, 
+ * and routes all other URIs to static files under ./example_www. 
+ * 
+ * index.php is used as the directory index.
+ *
+ * Just run it on the command line like "php example_server.php".
+ */
+
+require_once __DIR__ . '/httpserver/httpserver.php';
+
+class ExampleServer extends HTTPServer
+{
+    function __construct()
+    {
+        parent::__construct(array(
+            'port' => 8002,
+        ));
+    }
+
+    function route_request($request)
+    {
+        $uri = $request->uri;
+        
+        $doc_root = __DIR__ . '/www';
+        
+        if (preg_match('#/$#', $uri))
+        {
+            $uri .= "index.php";
+        }
+        
+        if (preg_match('#\.php$#', $uri))
+        {
+            return $this->get_php_response($request, "$doc_root$uri");
+        }
+        else
+        {
+            return $this->get_static_response($request, "$doc_root$uri");
+        }                
+    }        
+}
+
+$server = new ExampleServer();
+$server->run_forever();
\ No newline at end of file
diff --git a/server/php/example/test_sms.php b/server/php/example/test_sms.php
new file mode 100755
index 0000000..d56d634
--- /dev/null
+++ b/server/php/example/test_sms.php
@@ -0,0 +1,6 @@
+<?php
+
+require_once __DIR__."/config.php";
+require_once __DIR__."/lib.php";
+
+var_dump(get_outgoing_sms("16505551212"));
\ No newline at end of file
diff --git a/server/php/example/www/index.php b/server/php/example/www/index.php
new file mode 100755
index 0000000..3f5a1b4
--- /dev/null
+++ b/server/php/example/www/index.php
@@ -0,0 +1,91 @@
+<?php
+
+require_once dirname(__DIR__)."/config.php";
+require_once dirname(dirname(__DIR__))."/KalSMS.php";
+
+ini_set('display_errors','0');
+
+// this example implementation uses the filesystem to store outgoing SMS messages,
+// but presumably a production implementation would use another storage method
+
+$kalsms = KalSMS::new_from_request();
+
+$phone_number = $kalsms->get_request_phone_number();
+
+$password = @$PASSWORDS[$phone_number];
+
+if (!isset($password) || !$kalsms->is_validated_request($password))
+{
+    header("HTTP/1.1 403 Forbidden");
+    error_log("Invalid request signature");
+    echo "Invalid request signature";
+    return;
+}
+
+$action = $kalsms->get_request_action();
+
+switch ($action->type)
+{
+    case KalSMS::ACTION_INCOMING:    
+        error_log("Received SMS from {$action->from}");
+        
+        $reply = new KalSMS_OutgoingMessage();
+        $reply->message = "You said: {$action->message}";
+    
+        error_log("Sending reply: {$reply->message}");
+    
+        header("Content-Type: text/xml");
+        echo $action->get_response_xml(array($reply));
+        return;
+        
+    case KalSMS::ACTION_OUTGOING:
+        $messages = array();
+   
+        $dir = opendir($OUTGOING_DIR_NAME);
+        while ($file = readdir($dir)) 
+        {
+            if (preg_match('#\.json$#', $file))
+            {
+                $data = json_decode(file_get_contents("$OUTGOING_DIR_NAME/$file"), true);
+                if ($data && @$data['from'] == $phone_number)
+                {
+                    $sms = new KalSMS_OutgoingMessage();
+                    $sms->id = $data['id'];
+                    $sms->to = $data['to'];
+                    $sms->from = $data['from'];
+                    $sms->message = $data['message'];
+                    $messages[] = $sms;
+                }
+            }
+        }
+        closedir($dir);
+        
+        header("Content-Type: text/xml");
+        echo $action->get_response_xml($messages);
+        return;
+        
+    case KalSMS::ACTION_SEND_STATUS:
+    
+        $id = $action->id;
+        
+        // delete file with matching id    
+        if (preg_match('#^\w+$#', $id) && unlink("$OUTGOING_DIR_NAME/$id.json"))
+        {
+            echo "OK";            
+        }       
+        else
+        {
+            header("HTTP/1.1 404 Not Found");
+            echo "invalid id";            
+        }   
+        return;
+        
+    case KalSMS::ACTION_TEST:
+        echo "OK";
+        return;
+    
+    default:
+        header("HTTP/1.1 404 Not Found");
+        echo "Invalid action";
+        return;
+}
\ No newline at end of file
diff --git a/src/org/envaya/kalsms/App.java b/src/org/envaya/kalsms/App.java
index 3d32f0f..7300214 100755
--- a/src/org/envaya/kalsms/App.java
+++ b/src/org/envaya/kalsms/App.java
@@ -16,8 +16,10 @@ import android.os.SystemClock;
 import android.preference.PreferenceManager;
 import android.telephony.SmsManager;
 import android.util.Log;
+import org.apache.http.HttpResponse;
 import org.apache.http.client.HttpClient;
 import org.apache.http.impl.client.DefaultHttpClient;
+import org.apache.http.message.BasicNameValuePair;
 import org.apache.http.params.BasicHttpParams;
 import org.apache.http.params.HttpConnectionParams;
 import org.apache.http.params.HttpParams;
@@ -71,6 +73,22 @@ public class App {
         context.sendBroadcast(broadcast);        
     }
 
+    public void checkOutgoingMessages()
+    {
+        String serverUrl = getServerUrl();
+        if (serverUrl.length() > 0) 
+        {
+            log("Checking for outgoing messages");
+            new PollerTask().execute(                
+                new BasicNameValuePair("action", App.ACTION_OUTGOING)
+            );
+        }
+        else
+        {
+            log("Can't check outgoing messages; server URL not set");
+        }
+    }
+    
     public void setOutgoingMessageAlarm()
     {
         AlarmManager alarm = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);        
@@ -212,4 +230,20 @@ public class App {
         log("Sending " +sms.getLogName() + " to " + sms.getTo());
         smgr.sendTextMessage(sms.getTo(), null, sms.getMessage(), sentIntent, null);
     }
+    
+    private class PollerTask extends HttpTask {
+
+        public PollerTask()
+        {
+            super(app);
+        }
+        
+        @Override
+        protected void handleResponse(HttpResponse response) throws Exception {
+            for (OutgoingSmsMessage reply : parseResponseXML(response)) {
+                app.sendSMS(reply);
+            }                                        
+        }                
+    }
+    
 }
diff --git a/src/org/envaya/kalsms/HttpTask.java b/src/org/envaya/kalsms/HttpTask.java
index c9737dd..74fd4db 100755
--- a/src/org/envaya/kalsms/HttpTask.java
+++ b/src/org/envaya/kalsms/HttpTask.java
@@ -84,6 +84,7 @@ public class HttpTask extends AsyncTask<BasicNameValuePair, Void, HttpResponse>
                         
             String signature = this.getSignature(url, params);
             
+            post.setHeader("X-Kalsms-Version", "2");
             post.setHeader("X-Kalsms-PhoneNumber", app.getPhoneNumber());
             post.setHeader("X-Kalsms-Signature", signature);
             
diff --git a/src/org/envaya/kalsms/IncomingMessageForwarder.java b/src/org/envaya/kalsms/IncomingMessageForwarder.java
index bb336fb..27e9120 100755
--- a/src/org/envaya/kalsms/IncomingMessageForwarder.java
+++ b/src/org/envaya/kalsms/IncomingMessageForwarder.java
@@ -53,7 +53,6 @@ public class IncomingMessageForwarder extends BroadcastReceiver {
         String serverUrl = app.getServerUrl();
         String message = sms.getMessageBody();
         String sender = sms.getOriginatingAddress();
-        String recipient = app.getPhoneNumber();
 
         app.log("Received SMS from " + sender);
 
@@ -64,7 +63,6 @@ public class IncomingMessageForwarder extends BroadcastReceiver {
 
             new ForwarderTask(sms).execute(
                 new BasicNameValuePair("from", sender),
-                new BasicNameValuePair("to", recipient),
                 new BasicNameValuePair("message", message),
                 new BasicNameValuePair("action", App.ACTION_INCOMING)
             );
diff --git a/src/org/envaya/kalsms/Main.java b/src/org/envaya/kalsms/Main.java
index b312299..686a7e5 100755
--- a/src/org/envaya/kalsms/Main.java
+++ b/src/org/envaya/kalsms/Main.java
@@ -133,6 +133,9 @@ public class Main extends Activity {
         case R.id.settings:
             startActivity(new Intent(this, Prefs.class));
             return true;
+        case R.id.check_now:
+            app.checkOutgoingMessages();
+            return true;
         case R.id.test: 
             app.log("Testing server connection...");
             new TestTask().execute(
diff --git a/src/org/envaya/kalsms/OutgoingMessagePoller.java b/src/org/envaya/kalsms/OutgoingMessagePoller.java
index 5a4c085..a8c9018 100755
--- a/src/org/envaya/kalsms/OutgoingMessagePoller.java
+++ b/src/org/envaya/kalsms/OutgoingMessagePoller.java
@@ -3,40 +3,14 @@ package org.envaya.kalsms;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
-import org.apache.http.HttpResponse;
-import org.apache.http.message.BasicNameValuePair;
 
 public class OutgoingMessagePoller extends BroadcastReceiver {
 
     private App app;
 
-    private class PollerTask extends HttpTask {
-
-        public PollerTask()
-        {
-            super(app);
-        }
-        
-        @Override
-        protected void handleResponse(HttpResponse response) throws Exception {
-            for (OutgoingSmsMessage reply : parseResponseXML(response)) {
-                app.sendSMS(reply);
-            }                                        
-        }                
-    }
-
     @Override
     public void onReceive(Context context, Intent intent) {
         app = App.getInstance(context);
-
-        String serverUrl = app.getServerUrl();
-        if (serverUrl.length() > 0) 
-        {
-            app.log("Checking for outgoing messages");
-            new PollerTask().execute(
-                new BasicNameValuePair("from", app.getPhoneNumber()),
-                new BasicNameValuePair("action", App.ACTION_OUTGOING)
-            );
-        }            
+        app.checkOutgoingMessages();
     }
 }