The Shift morphing tricycle bicycle(for kids of course)

[Shibby]

This is pretty cool. My wife saw this in readers digest. It sits with the stabilty of a tricycle. Basically it has two back wheels in an A-frame shape. But as you go faster, they come together to make one big tire.

http://www.engadget.com/2005/04/16/t...cycle-bicycle/