I promised a fellow twitterer a potty training tip that worked for A, so here goes:
A was completely potty trained by 2 yrs 3 mos and here is what I found to be the trick. Kids of course love praise and stickers work, candy, etc., but one day my husband and I were visiting his grandmother and A became obsessed with going potty because there is a singing fish in the bathroom. (Bad Mouth Billy Bass if you will.) Anyway, she wanted to go in and "push the button on the fish." It became a game for her, but we would only let her push the button if she actually went potty. This worked so well that we borrowed the fish and hung it in our bathroom at home.
Pretty soon she was asking to go potty multiple times during the day because she loved pushing the button on that fish. Eventually it became second nature to realize she needed to go potty and voila!
I'm not saying you have to run out and buy this fish (although I'm sure you can find one on ebay). Perhaps some other musical toy or something new that would get them excited to go potty would do the trick. Just be sure not to let them play it unless they actually go potty or you'll have them making 50 unnecessary trips to the toilet.