I’m 404ing. According to The Jargon Lexicon and The Geektionary, to 404 is to draw a blank. Thus “I’m 404ing” translates to “I’m drawing a blank.” I also think it should be used like…

Guy 1: Dude, where’s my car? Guy 2: I totally 404ed it. Sorry man. Guy 1: Sucks, but nice new term. Guy 2: Thanks.

Don’t be surprised if you hear this soon.

Other favorites from the Jargon Lexicon: @-party, asbestos longjohns, and Knights of the Lamda Calculus.