Google Talk

Google TalkTM for BlackBerry® smartphones allows you to chat in virtual real time with your instant messaging IM contacts when and where you want to not just when you're in front of your computer. It has many of the same features you already use with Google Talk on your desktop. 

Features include: 
-Fast and reliable messaging
-Your Friends  presence updates  e.g. Available or Offline, in virtual real-time
-The ability to customize your own status messages  e.g. Back in 5 mins, On the Phone
-Emoticons to express yourself
-The ability to invite multiple users into one conversation
-The ability to personalize Google Talk with a buddy picture, use an image of yourself or display your favorite icon
-Communicate with other Google Talk users even while using other applications on your BlackBerry®
-Set up custom notifications for new Google Talk messages.

For all technical support with Google Talk, please visit http://us.blackberry.com/support/software/google_talk.jsp
For billing issues and technical support options related to App World only, please visit http://www.blackberry.com/support/appworld. 
Direct support is unavailable through the “Contact Support” button.