12-08-2008 10:15 AM - edited 12-08-2008 10:48 PM
You have to implement chat-client and chat-server applications.
For the first to look at Blackberry Developer Guide (there are 2 books/parts).
It can be downloaded here:
And use Google to find samples of java based chat-applications to get a technical ideas for the implementation.
12-08-2008 10:49 AM
You also need to figure out how to get UDP packets passed, since this is the only reasonable way to implement something like this. LOL.