Bill Clinton - Shook hands with him and had a 3-minute conversation with the rest of the saxophone section of the University of Texas Longhorn Band while he was giving a speech at the Frank Erwin Center in 1995/1996.
Frank Gifford - I used to work for a DJ in high school. He was the recipient of a roast that we were working.
Britney Spears - I made an appearance on the Mickey Mouse Club Show in '92. It was there that I learned what an interabang is (note: it's not a hair style.)
William Shatner - [link|http://www.spplatattack.com/game.php|SPPLAT Attack 2002]. [link|http://celebritypaintball.com/|And again this year].
George W. Bush - He was running around the track at the [link|http://www.mackbrown-texasfootball.com/pages/superstadium.html|Darrell K Royal - Texas Memorial Stadium] one evening while the LHB was practicing. One of the saxes stopped him to chat. I was in the area.
Douglas Adams - He gave a speech at UT in '94 on the Information Superhighway. I won a copy of one of his books (that I'd already read, of course.)
Richard Garriott - Lord British of Ultima fame. He gave a speech at one of the [link|http://utacm.org/|UT ACM] meetings. I won a copy of Ultima VIII and handed it to me. I've still never played it.
I think that's it...