BOUO-Ball of Unknown Origin. From the Fox TV show House MD. A large red and grey tennis ball that sits on Dr. Gregory House's (Hugh Laurie) desk. The BOUO is a subject commonly discussed in the TWoP House forums, or by any other House fanatic. We just want to know where it came from!
Me: I really want a BOUO! I see it every Tuesday on House and I want one of my own!
Friend: Where did the BOUO come from anyway?
Me: Umm, it wouldn't be a 'Ball of Unknown Origin' if we knew where it came from!