"guess i wont ever being calling my girlfriend again…" —commenter

United States Application US201000293022 was published today for Apple Computer.  Originally filed on August 8, 2008, the patent is for the ability to share location information during calls, text message or TCP/IP streams via the touch of a button.  From the filing:

1. A method for communications between a first mobile device and a second mobile device, comprising: during an ongoing telephone call communication session between the first and second devices, responding to a user's activation of a virtual or actual button or key on the first device, or a user's verbal command given to the first device, by the first device automatically sending an over the air message to the second device that requests location information of the second device, and then upon obtaining location information from the second device, the first device automatically displaying a location of the second device. 

2. The method of claim 1 further comprising: during the ongoing communication session between the first and second devices, receiving by the first device one of a) a SMS or text message, b) a TCP/IP message, c) a UDP message, and d) a cellular network control message, from the second device that contains location information of the second device. 

 See more images below:

Also interesting that they mention WiMAX as one of the one of the RF means of sharing location information.  Guess you must cover your bases :D

Via Appleinsider