It can send a message to all message addresses (phone number, e-mail address, instant messaging screen name) for all message types (voicemail, e-mail, instant message, SMS, MMS, fax).

FORBES: Magazine Article

Cellular conversations, instant messaging, SMS and use of social media are part of our daily communications and will be subject to recording and monitoring in the financial industry.

FORBES: All Phone Calls With Brokers In The UK Now Recorded; Coming Soon To Europe and America

So far, AOL has struck deals to deliver instant messaging via SMS with two network operators, VoiceStream Wireless in the United States and Hutchison Telecommunications in Hong Kong, according to Jon Eric Bylin, senior product manager at America Online's AOL Mobile division.

CNN: AOL brings instant messenger to mobile phones