We did a sticker chart with my DD1 when we started potty training, just before she turned 2. She got a kick out of it, started peeing every 30 minutes just to get a sticker! She's 3 1/2 now and we have a behavioral chart with about 10 different categories... but with a 2 year old, I'd start small, just one or two activities... He might be a bit young to have any kind of long term reward, other than just the sticker. ( Like, "after you get 25 stickers, we'll have a zoo trip!") Short term rewards, like a penny in a piggy bank for every sticker, given at night before bed, might work, but honestly, the sticker itself would probably be reward enough for him; it is for my daughter. When she gets older, I'm sure we'll have to find other motivations, though!