Greg Knauss’ The Devil’s Dictionary (which I’ve mentioned before) has some wonderfully nasty definitions of things computer- and Web-ish. He updates it every now and again, and he’s added some new entries since last I checked. My favourites:
GNU License, noun
An impairment of vision, causing the victims perception to be limited to black and white.
usability, adjective
The quality of being easy, usually championed by the difficult.
(One nitpick: “usability” is a noun; “usable” is an adjective.)
extreme programming, noun
A method of software development that combines all the charm of backseat driving with all the efficiency of a marital squabble.