As a teacher and a grad-school TA, we use AIM to communicate through "virtual office hours" and I have found it quite useful. I don't believe that this should be a child's only means of communication...they should get out (step away from the computer) and meet people in person as well. I really don't think AIM is awful when it's supervised and the kids are taught that there's a time and a place for "AIM Lingo".