Barack Obama puts out an ad mocking John McCain as a computer illiterate.  (The ad is here -- for now, at least.)

Only problem -- for Obama, that is -- is that McCain can't use a keyboard because of the wounds he sustained in service to his country.  According to a 2000 piece in The Boston Globe:

McCain's severe war injuries prevent him from combing his hair, typing on a keyboard, or tying his shoes.

Oops.  Think of it this way, Barack:  McCain's willingness to risk that injury you've tried to ridicule is what gave you the freedom to serve as a "community organizer."