Desktop Notifications is an experimental tool built by a Facebook engineer. It provides a discrete menubar icon that turns blue when you have a new notification, and allows you to see your past notifications, inbox, as well as providing direct links to updating your status, and reaching your news feed and profile.
The application integrates with Growl, allowing small notification bubbles to pop up when activity you’ve chosen to be notified for has occurred on your Facebook. Clean and lightweight, this application is handy if you want to always know what’s going on with your Facebook, not so much if you can’t afford to waste time on social networking.
Download Desktop Notifications here.