Take the 'flip-flopping' issue that became so huge last election and use it against the Republicans. Media clip montages showing a clear reversal on many of the issues his campaign lauds him for. Let McCain condemn himself with his own words in the same style that's so incredibly effective on a nightly basis.

The Daily Show does this a lot, by juxtaposing recent clips of people's opinions (like how Fox News and McCain strategists say that the questioning of Sarah Palin's qualifications for Vice-President is sexist) with the same people speaking the complete opposite when it didn't benefit them to do so (them saying Hillary Clinton should stop complaining about sexism).