David Letterman apologized for his joke about Sarah Palin's daughter, but that didn't stop him from poking fun at his protesters. His top 10 list Tuesday was on "things overheard at the 'Fire David Letterman' rally." It included:"Isn't there always a crowd demanding Letterman be fired?""Can we also get CBS to bring back 'Gunsmoke'?""When does Cheney get here with the waterboarding gear?""He should apologize for that hairpiece."