My son learned how to ride on a Strider bike. He started riding it when he was 2 years old. Six months later he was riding a regular pedal bike without training wheels!
Now my 2 year old daughter is riding it.
You can purchase one at Over the Edge bike shop in Hurricane. The price is a little high at $100, but my sister found a new balance bike by Walmart that may be a great alternative. It is only $30! http://www.walmart.com/ip/10-WeeRide-Learn-2-Ride-Bicycle/14248176