Clinton and Obama on tonight's Colbert Report

PHILADELPHIA — Sen. Hillary Rodham Clinton played up her image as a tireless problem solver _ this time for laughs _ when she visited Comedy Central's "The Colbert Report" Thursday night.

Not to be outdone, Sen. Barack Obama, her rival for the Democratic nomination, showed up via satellite to poke fun at what he called the media's fixation on gaffes and trivialities.

Clinton emerged just as host Stephen Colbert, broadcasting from the University of Pennsylvania ahead of the state's primary Tuesday, was lamenting that he had no technicians to repair the lost signal on his giant rear projector screen.