The Null Device
Merriam-Webster's 2007 Word of the Year is w00t:
expressing joy (it could be after a triumph, or for no reason at all); similar in use to the word "yay": "w00t! I won the contest!"The article gives the etymology of "w00t" as an acronym for "we owned the other team"; I agree with Cory Doctorow that this seems like a back-formation of the word. I suspect that the word comes from the UNIX superuser account name "root", via hacker/cracker culture (as in "I've acquired root privilege (on some machine)" -> "root" -> "w00t").
Incidentally, w00t is probably the only word in the dictionary with digits as letters (though please correct me if I'm wrong); which means that Scrabble players may soon need the L33T Tiles.
(via Boing Boing)