The address card? Go to a message hit menu > attach contact and it will add a contact card from your address book. when you receive a message with a contact card scroll to where it shows in the message and hit menu > open attachment > menu > add to address book.
thanks! I was trying to help a bb messenger buddy who has att and I'm verizon and our phones are set up a bit different.
I am off to see if this will work on my phone as well. if so, I just learned a new feature! thanks so much!