Philadelphia Mayor Michael Nutter took the stage with four other speakers for a Google-hosted panel on communities of color and the economy and noticed an empty chair next to him. He looked at it, suggested it be removed, and then riffed on Clint Eastwood's GOP convention speech in which the actor talked to an invisible President Obama in an empty chair.

"I'm doing what you're supposed to do in a chair," Nutter said to applause, "which is sit in it. Not talk to it."