How is AIM different from SMS text messages?
With AIM, you can send and receive messages with tens of millions of users that use AOL, AIM, ICQ, .mac, or MobileMe on mobile devices and desktop computers around the world. You’re not limited to 160 characters when sending messages, and AIM’s presence service lets you know if your buddies are available before you talk to them. Of course, if you want to send text messages, you can do that through AIM also (see below).