in short, NO. instant messaging programs do not eat up your text messages. When you send a text message it goes through AT&T's servers and count as a text but when using an instant messaging app such as mobilechat or apollo, its only data which is not going through AT&T. So if you are using meebo.com or x.aim.com/ty for instant messaging, it does not count against your text message. So go forth and message away.