One of the best features of the Google maps on iPhone is the ‘Locate Me’ function. This uses some phone tower/WIFI access point jiggery-pokery and pin-points your current location on the map.

This works because the guys at Skyhook Wireless have driven around the glove scanning for access points. You can add your own to the list using this link.

Th more access points, the more accurate the feature will be.