A site hard SF afficianados might like.

[Dredj]

This may be the best hard SF site on the web.

http://www.projectrho.com/rocket/index.html

[Dredj]

Here's another one.

http://members.aol.com/oscarcombs/settle.htm

[epweissengruber]

Cool!

I am thinking of running a sci-fi Narrativist RPG at my school with the hopes of improving general and scientific literacy.

These sites will help.

[Joshua A.C. Newman]

Dredj, those are really neat!

[David Artman]

Thanks! And here's more food for thought:
http://www.transhumanism.org/index.php/WTA/index/