Can anyone tell me definitively whether messaging applications such as AIM make use of AT&T's SMS service? I count myself among the many who were disappointed that AT&T didn't include any SMS messages in the new 3G packages, so I'd like to find a messaging solution that won't result in me paying $.20 every time I send or receive a message. There seem to be several messaging applications, but to the novice, it's not clear which will result in an AT&T charge and which are totally free. Thanks in advance!!!