www.paperplane.org is a great page covering lots about paper airplanes. Check it out. The author of the website, Ken Blackburn, currently holds the world record for time aloft of a paper airplane at 27.6 seconds!
The best paper airplane in the world, (or so they say).
Joseph Palmer's Paper Airplanes are some of my favorite designs.
This is very cool, you can print out this model of a Piper J-3 Cub on two standard size sheets of paper. It builds very quickly and is lots of fun.
(PDF, 499 kb).
(PDF, 525 kb).
(PDF, 964 kb).
Curtesy of Fiddler's Green, check them out, they have a lot of cool stuff.