Blackboard Instant Messenger is a synchronous chat program similar to Google Talk and AIM. One major difference is you can set up office hours where you can chat with one student at a time as well as your course rosters are pre-populated within the tool. This tool can be accessed outside of Bb.
Learn more about using Bb IM for office hours.
Open these PDF handouts for more information.
Share with your students who are first time users of this tool:
Now that you and your students have set up Bb instant messaging, practice using the tool during the first week of class to discover what works best for you and your students.