Dave lost one of his favorite monologue topics yesterday as the beer summit came and went. Once the president invited Henry Louis Gates and the man who arrested him over to the White House for a brew, the late night comics let loose on what was previously an unaddressed racial conflict. "Alcohol usually cools things off...have you noticed that?" Letterman joked Tuesday night. After a few jabs at Joe Biden and an imagining of the three men starring in the "Hangover 2" with Zach Galifianakis, Dave got to the culmination of all his beer-summit jokes: A top ten list.