It's like the "Elderly Tourette's"-suffering Joe Biden character on Saturday Night Live who leans around Obama during a Presidential address to blurt out "Look, I know $819 billion sounds like a lot of money. But it’s just a tip of the iceberg.Signing Stimulus, Obama Doesn’t Rule Out More By SHERYL GAY STOLBERG As President Obama signed his recovery bill, an aide said that he had not ruled out a second stimulus package.