As Sufficiently Advanced begins and ends with quotations from Clarke, I thought it appropriate to at least mention this here. For those who never read his work very much, CNN has a nice article. The Rama series was always one of my favorites, and Light of Other Days has some very cool time-bending stuff. I think I might go re-read that now.
"Sometimes I think we're alone in the universe, and sometimes I think we're not. In either case the idea is quite staggering." —Arthur C. Clarke, 16 December 1917 – 18 March 2008