First Black president
Add 1 to the candidates for the first black president. Condi Rice.
Since the President's term ends at 12:00 noon, and Obama had not yet taken the oath, we would start going down the succession list. Dick Cheney's term also ended. Speaker of the House Pelosi did not resign her position, nor did Dingy Harry Reid. That means the "acting President" prize went to Condi Rice as Secretary of State, for the 6 minutes or so before Joe Biden took his oath. Then Joe Biden held the honors until Senator Obama took the oath properly the next day.
They say that scabs don't heal if you keep picking at them!