Cool stuff.

http://www.sunbelt-software.com/stu/iraq/sandstorm.htm (Neat pictures of a sandstorm)

http://www.fincher.org/Misc/Pennies/ (Fascinating penny constructions)

http://www.naturenet.net/links/java/connect4.htm (Try beating the computer on this one)

http://www.picturesonwalls.com/ (Cool art)

http://www.zefrank.com/dtoy_vs_byokal/ (Makes interesting designs)

http://www.memecentral.com/Level3.htm (Good reading)

http://www.asa100.com/ (An amazing photographer. I highly suggest you watch the opening video)