TweetFuck
THIS CLASS IS DEPRECATED. WORKING ON A NEW ONE...
Use Twitter API without OAuth and without restrictions.
Basic example:
<?php
$T = new TweetFuck;
if (!$T->signin('username_or_email','password')) die("Unable to sign in\n");
print_r($T->post('statuses/update',array('status'=>'Hello world')));
print_r($T->get('account/rate_limit_status'));
?>