If you ever wanted to create a functionality to mention a user like you find on Twitter or Facebook, you now can do it with jquery.mentionsInput. This small but awesome UI component, allows you to easily @mention someone in a text message. This has been become open source for a while (was an internal project written by Kenneth Aucheberg at Podio).
This jQuery plugin has been tested in FF6+, Chrome 15+ and IE 8+. Due to the fact that is written in jQuery, it requires the library to work. But, it also requires underscore.js that is used to simplify stuff. The jQuery @mention plugin is using the new HTML5 “input” event.