Barack Obama sat down with David Letterman and of course has was asked to explain what he meant when he said McCain's ideas for "change" were like putting lipstick on a pig. He was funny, he was self-deprecating and he said now that Time and Newsweek are putting Sarah Palin on their covers, he's entertaining an offer to be the centerfold for an upcoming issue of Popular Mechanics. Um, actually, if Popular Mechanics featured a shirtless and slightly dirty Obama bending over under the hood of a car, I would totally buy that. A couple of times.