I love the Internet. Why didn’t they have this when I was in college?
I don’t normally review other websites on here, but this site is screaming for a post. Two friends from Michigan recently launched The Kegulator. Input the number of people coming to your party and how drunk you want them to be, and it tells you how much beer you need. Not only that, it does it in convenient case/pony/keg increments. And accounts for beer loss. And tells you how many cups and how much ice to buy.
Best use of AJAX ever.
Update: Has anybody else noticed that lately all I seem to be posting about is beer?