Rupp - no experience with them here. But if your goal is to get the kids off a computer that all they do on is IM, and they only IM using AIM, then it's probably a good idea. Much better to have them on one of those little things than have them tie-up a whole computer...
As a bonus, it will prevent someone from IM'ing them a questionable link that they could click on if they were using a PC.