Play of the Day -- Biden hits the stump

Conan has suggestions for the vice president.

David Letterman could not get enough of Mitt Romney's infectious laugh, Conan O'Brien proposed a handful of campaign slogans for Vice President Joe Biden, and former presidential candidate Rick Santorum decided to show up and share a piece of his mind.

Today's Must See Moment -- Fast forward to 1:00 to see the guest of the night on Fox News.