Just when you thought it was safe to dine at Michael’s, TV gasbag Keith Olbermann was back sporting a full beard yesterday. He was celebrating with Al Gore after signing with the former veep’s little-watched Current TV. A spy told us, “Gore and Olbermann marched in with five other men in black suits. Gore looked chipper and had makeup on, Olbermann had a week’s worth of gray beard. Gore went over to Barry Diller‘s table and said, “I’m so excited we’ve signed Keith — he’ll be on five nights a week.” Diller said, “That’s just great.” Also probably thinking “great” was Lawrence O’Donnell, who took over Keith’s MSNBC slot and sat quietly at a table further back.