I use an AT&T Curve 8310 that was unlocked, I use it on T-Mobile. I know AT&T users have had a native AIM client for a long time. I just helped my friend buy a Curve 8320, he is on T-Mobile like me, and I helped him get used to it and get set up with it. I noticed he has a ton of native IM clients, including AIM, ICQ, Yahoo, etc! I did some web searching, and I found out about http://www.blackberry.com/aim but when I went there and accepted the terms, it said my phone wasn't compatible.
Anyway, does anybody know how I can get AIM or any of those apps? I use Ramble IM right now but I saw my friend's AIM on his 8320 and it looked nicer.