Current: Mobile telephone systems have Caller ID. When you receive a call, the number (and sometimes name of the caller) is displayed on a numeric LCD screen before you answer your phone.
Future: Mobile telephones have integrated GPS positioning cabaility, and cellular telephone systems continue to have Caller ID. When you receive a call, the number and location (and sometimes map of the caller's location) is displayed to you on an OLED screen.
Imagine not only knowing who is calling-
but precisely where they are calling from.
Past- "Hello? Who is this?"
Present-"Tom, where are you?"
Future-
BREAKDOWN
What else will integrated GPS mean for the way we communicate with our mobiles?
update This future isn't very futuristic- it will be a reality within 18 or 24 months. The phones are already out (or in deployment), and some moblogs in Tokyo already post photos with GPS coordinates attached. Maybe I need to start learning Lat/Long coordinates of major cities...