So here is the situation, might be a simple solve or difficult, thats why I'm asking. :P

My friend and I are switching Iphones, He has a 3g and I have a 2g. Dont ask me why, its complicated.

We are both ATT customers so thats fine. Now my question is,
Will there be any complications with doing the switch?
Will texts and other information be backed up so I can transfer it on to the other phone when I get it? Do I have to report to AT&T that I have a new phone?

Appreciate the help!