Haven't actually pulled an all-nighter in the library yet (although it may be coming up in a couple days), but I think the idea of "Wake the Library" is great--it's open 24/7 during final exams, and free food is provided in the early morning hours. Check out the pics here!
(I'm probably just proving what a nerd I am by being excited about this. I also still get excited about wearing jeans to Wal-Mart. Although I think the latter proves that I'm scarred for life and not necessarily that I'm a nerd.)