The new version of Google Maps application for mobile phones is enhanced to detect your location and show it on the Map even if your mobile does not have GPS support.
The new feature called My Location detects your location using the information from mobile towers near you to approximate the current location on the map.
The approximation of location is expected to be close to 1000m on average and it is expected improve when the feature comes out of beta.
This features is available for most web-enabled mobile phones, including Java, BlackBerry, Windows Mobile, and Symbian devices.
To get the new version of Google Maps for Mobile devices go to http://google.com/gmm on your mobile device.