Developers Create Unofficial Find My iPhone API
The iPhone is correctly credited with bringing location services to the consumer. It started at launch with Google Maps. It kicked into hyper-drive with the launch of the App Store (there are now over 2800 location-enabled apps). However, there is still a step to go, the iPhone needs the ability to share your location in the background to a third-party server. This has been done for them by a couple of hackers.
Apple already tracks the location of any Mobile Me user who has enabled the feature Find My iPhone. Tyler Hall has released Sosumi, Mobile Me scraper, to Github. Sosumi can access a user's location and send messages to the iPhone.
So what does this mean? For "normal" users absolutely nothing. Just like Google Latitude's nascent Location API this is really just a proof of concept application for developers. Before a Mobile Me Location API will get widespread use it will need OAuth, the ability to control the accuracy of my location data, and reminders and, most significantly, it will need Apple's official sanctioning.