Among the things that Wikipedia is not is a usage guide. Much less is it a usage guide for teenage slang--allowing that is to permit Wikipedia to degenerate into something resembling H2G2 and Everything2, which, as Zeus is my witness, I will never allow to happen. If you want to write entries about that, please start a dictionary wiki. We still don't know why no one has started one.
Content of original article is below. --LMS
An exclamation of agreement and/or happiness. Usually used by a younger crowd, script kiddies and people who play EverQuest?. Sometimes used to denote victory.
This word originates from a mangling of the interjective Woo (which itself came from Whew). Its popularity began to rise with the prominence of online multiplayer games--in particular, online role-playing games such as EverQuest?. This is probably as a result of the phenomenon of online communication morphing words to create strong statements that are easy to type. See also -- grok, blorf?, editors, feel free to add some other new-age jargon that have interesting roots
W00t is the lamer? version of woot. In the language of the lamers, certain letters are replaced with numerals or mathematical symbols to create an elitist alphabet. W00+ is also a lamer variation of woot.