My friend had a ZUM Balance Bike and I thought it was just a funny looking gimmick. It's a bike with no pedals that kids push with their feet. Then, one day, I saw her daughter ride the balance bike for one afternoon and then pick up her sister's two wheel bike and ride away. She needed no training wheels or instruction. She just rode away. At this point, I told Joe to get on the awesome little ZUM Balance Bike.
Joe (age 4) and Brooke (age 2) rode this bike for about a month and thought it was a fun little Police bike. Last weekend, at his grandparents house, Joe just jumped on a two wheel bike and rode away. His balance (and speed) were perfect. His start and stop were a little shaky, but after a couple tries (and one minor fall), Joe was a 2 wheel'n biker dude. Check out his first day here (and ignore the Hello Kitty bike).