Here's an overview of the different types of messaging available through AT&T:
AT&T Text Messaging includes:
Mobile to mobile text messaging - Send and receive short text messages between your wireless device and virtually any other wireless device in the U.S. Just send your text message to your recipient's 10-digit wireless phone number. You can even exchange messages with those in many international destinations.
Instant messaging/mobile instant messaging - Send or receive instant messages using AOL Instant Messenger (AIM) or Yahoo! Messenger.
IM forwarding - Forward your AIM or Yahoo! instant messages directly to your wireless phone to reply or send instant messages directly when you're away from your computer.
PC-to-mobile instant messaging - Send AIM or Yahoo! Instant Messages from your computer to friends and family, using their AT&T wireless phone number.
Email messaging - Send and receive short emails on your phone by using the phone's unique email address.
Information alerts - Get news, stock quotes, sports scores, entertainment news, or other information as it happens. Information is sent directly to your wireless device's display. Sign up for your favorite topics.
Group messaging - Send a text message to multiple recipients from your wireless phone.