R.R.
Vegas is rough for little ones (who can't even walk through casinos) especially 2 1/2 year olds and the elderly, there's nothing to do but go see shows, and the walking around is way too much for them, for little ones and the elderly. The only thing I can think of is lounging by the hotel pool.
Sorry, my guy is 29 months and we won't go for years until he can appreciate M&M World and the all-you-can-eat buffets.
But here's a list by Vegas,com that may help you:
http://www.vegas.com/attractions/kids.html