My wife and I put our son on a snowboard when he was 3. Without much effort he learned to stand on the board and ride it... Stopping and turning are still a work in progress, but we bought the kids harness at Mt. Baker, and even though it's not the best piece of gear, it works. If your creative you could probably make your own harness that would work better with webbing or a cordalette. Lifties slow the chair when he gets on and we let him ride without getting too out of control. It takes patience, and Kaskadskyjkozak is right, they don't last that long anyway. Kiddie boards and boots are all over craigslist and every rental shop has little kiddie boards. For us the main obstacle is what to do with him once he's had enough. Rather than push him to much we typically take turns riding while he plays in snow or naps.