I have been searching for some fun Paper Crafts for me and my son to do.  Here are some websites I've found so far.

http://www.thetoymaker.com/2Toys.html

http://www.yamaha-motor.co.jp/global/entertainment/papercraft/index.html

http://papertoys.com/

http://cp.c-ij.com/english/3D-papercraft/index.html

http://www.ss42.com/pt-boats.html Boats, Ships and Subs Paper Models

I'll add more as I find them.

Enjoy!