My daughter learned to ride on a razor scooter. If you can balance one of those tiny wheeled pieces of junk a bike is easy. I'd like to get my son a pneumatic tired scooter like this:

http://www.amazon.com/Kent-09128-Sup...6535655&sr=8-4

If I had it to do again I'd never even buy my kids a bike untill they could balance a scooter. Training wheels are a crutch that will certainly delay learing to ride a bike.