My DS is 3, and he manages to stand and wee now and is very proud of himself for weeing just like daddy hehe. Perhaps put something in the toilet for him to aim at or something? Might make it a bit more fun? He's been really good with going to the toilet since he started standing, coz he doesn't have to take his pants right off or anything.

We initially did a sticker chart on the fridge, this was in December, so he was 2yr9mths old then, and this worked fairly well. We had a milkyway taped to the end of the line of stars to keep the reward right in front of him hehe.