S.C.
I have gone through this once already and am working on my second round (2 year old boy). During Christmas I was looking for stocking stuffers and I wanted to get something that would help him with potty training since he was so ready! I picked up an egg timer (basically a 1 hour timer). I painted it and called it the "PeePee bell". Because I knew he needed to be on a set schedule and I had enough to do to keep my eyes on the clock, it sounded like a good idea (my husband laughed!). When we are home, I set the bell to go off in an hour - when he hears it, it is like a game and he goes running to the bathroom. He doesn't always go, but he tries. Now, we don't need the bell any more - he just has a mental clock that clicks almost every hour. He is still in pull ups, but can go almost all day without an accident. We play around with underwear, but haven't put them on all day yet - only up until nap time.
Try it - it worked for me.