Try out new Facebook features before your friends with Prototypes
On the heels of last week's release of @mentions and the new Facebook Lite, today Facebook announced "Prototypes".
Prototypes give users a chance to test out cool new applications and functionality "going on inside the walls of Facebook" and to provide feedback to the who built the prototypes, directly.
To begin testing and providing feedback, simply find any application available in the Application Directory that is marked as "Prototype". Some cool examples that have come out of Facebook prototype apps include Desktop Notifications for Mac, recent comments filters and enhanced event emails.
Think of Prototypes much like the recently released Mozilla Test Pilot; Giving users the chance to opt-in to new features not quite ready for primetime.