For someone who is always thinking of clever things to ask when interviewing people, this was an interesting site. Thanks Sen! Sen found it on slashdot.
"This is a collection of riddles I've accumulated via Eta Kappa Nu / Tau Beta Pi challenges, the internet, academic courses, and lots of cool friends. Many of them are from job interviews for hi-tech positions; I believe Microsoft was responsible for popularizing the usage of riddles in interviews. I like these problems because they often require you to think in ways you wouldn't normally. They may seem impossible at first, but then you get a solution and it's an epiphany. "