One thing that you are going to notice is more information in your iPhone's call history log. This specifically relates to giving you the information about how long your specific phone calls were. This can be very important for scheduling, estimating AT&T billing issues, and giving you are time table for your communications. When you check under Recents, select the phone call you want to look at. On the Info page right under the type of call it is, it will list the time and length of the phone call.