Google has lannounced a URL Shortener API (Goo.gl).
This plugin by kovshenin creates goo.gl short URLs for your posts, which then could be retrieved using the “Get Shortlink” button in your admin UI or the wp_get_shortlink() WordPress function.
Requires PHP5 WordPress Version: 3.0 or higher Compatible up to: 3.0.4.
Download and info: http://wordpress.org/extend/plugins/googl/