Take your instant messaging with you. Instant messaging (IM) applications on BlackBerry® smartphones1 keep you in touch with your IM contacts—no matter where you are or what you’re doing.

Enjoy many of the instant messaging features you already enjoy on your computer on your BlackBerry smartphone, including:

A familiar user interface
Availability status
Contact access and management
Notifications to tell you when you receive a new message
Emoticons that help you express yourself
Stay in touch with your personal and business contacts
BlackBerry smartphones support the following instant messaging applications2.

BlackBerry Messenger
Yahoo!® Messenger for BlackBerry® Smartphones
Google Talk™ for BlackBerry® Smartphones
Windows® Live Messenger for BlackBerry® Smartphones
AOL® Instant Messenger for BlackBerry® Smartphones
ICQ® for BlackBerry® Smartphones
IBM® Lotus® Sametime
Microsoft® Office Communicator and Live Communications Server 2005
Novell® GroupWise® Messenger

nice! now how do i get aol instant messenger on my bold?

If you currently are subscribed with at&t, the AOL instant messenger service is blocked.  You can download other 3rd party applications which have those instant messengers such as AIM, MSN, Yahoo!, ICQ, etc.