Tutorial Send a Text Message
You'll need a TextMagic account and to download their PHP helper which they provide after signing up.
// Include the TextMagic PHP lib
require('textmagic-sms-api-php/TextMagicAPI.php');
// Set the username and password information
$username = 'myusername';
$password = 'mypassword';
// Create a new instance of TM
$router = new TextMagicAPI(array(
'username' => $username,
'password' => $password
));
// Send a text message to '999-123-4567'
$result = $router->send('Wake up!', array(9991234567), true);
// result: Result is: Array ( [messages] => Array ( [19896128] => 9991234567 ) [sent_text] => Wake up! [parts_count] => 1 )