where can i get a cheap and simple robot kit?

my friend and i are building a robot and i need a kit, i was thinking about going to radio shack but i don’t know if they have kits.

Check up the following sites,

Home

http://www.robot-electronics.co.uk
http://www.acroname.com
http://www.parallax.com

Homepage

http://www.robotshop.ca
http://www.pololu.com
http://www.irobot.com
http://www.botmag.com
http://www.societyofrobots.com