Adam Ostrow over at Mashable just put together a great list of 10 Awesome Things Built on the Facebook API.

He includes The Facebook Toolbar, which lets you extend your distracting Facebook experience to your browser (yay!), Rendezbook, which resembles speed-dating, and Facebook to Twitter, which lets you send your Facebook status to your Twitter friends (I use it!).

I would also add, to the list:

Books On Campus, which lets you buy and sell used textbooks on your college campus, and Mosoto, which lets you discover music through your friends (and share other files).

But for those of you with finals, I’d recommend a friend changing your Facebook password, so that you can’t login until after exams.