Obama made a small error in the first part of his inaugural speech. He said:
Forty-four Americans have now taken the presidential oath.
Because of Grover Cleveland's two non-consecutive terms, there have been 44 Presidents but only 43 people have held the office and taken the oath. I'm surprised his speechwriters didn't catch that little detail. Of course, I think of Al Gore as an ex-President so maybe that's where it came from.