It is about time!  I have never understood why ATT would not make it easy for people to use Yahoo and MSN or any messanger on their Blackberry.  Hell you bought the Blackberry, you are paying the monthly bill let people stay in contact with them damn Peeps already!

You can go to http://www.blackberry.com/instantmessaging from your Blackberry to see what IM clients will work on your blackberry.  Thanks to Berry Review for the great post.