Google have released an update to their Maps for Mobile application, which brings Assisted-GPS to handsets which lack hardware GPS receivers. Called "My Location", it triangulates a user's position via proximity to cell towers, plotting estimated position on a map downloaded via the phone's data connection.
Check out a video of the app in action, after the cut...
Since the technology is not as accurate as true GPS, Google indicate a "margin of error" which can be anything from 500 to 2,000 feet. The My Location technology is available on most smartphones, including all color BlackBerry devices, all Symbian Series 60 3rd Edition devices, most Windows Mobile devices, newer Sony Ericsson devices and some Motorola devices.
While Google state there are no privacy concerns, as personally identifiable information is not collected or stored, the system does take advantage of other users with GPS-enabled cellphones to refine their accuracy. If you then go on to use Maps for Mobile to search for a store or other location, Google will pair up your position with that search query.