The Mythbuster guys would be awesome to have speak. Heck, we could help them bust the myths of nerds not having girlfriends
.
In all seriousness, the guys of Mythbusters really know how to make science and physics exciting. Seeing them speak would be very cool, and saying celebrities (well, celebrities to a limited cable audience, anyway) would definately make FIRST appealing to a wider audience, and get more people involved.
I, personally, would like to see President Bush speak. I know that it might be incredibly hard to arrange, but I know that he has a deep involvement in the education of America, and FIRST really shows our generations potential.
But I'll bet that has been suggested before, so one more person I would like to see speak would be
Bill Nye: The Science Guy. I remember watching the show, and he made science fun and entertaining to me. And, he did create the hydraulic pressure resonance suppressor, and we use alot of hydraulics, so it would only be appropriate.