Google says that this feature should work on most "Java, BlackBerry, Windows Mobile, and Nokia/Symbian devices", but it doesn't work in Sony Ericsson K750i, so this claim is questionable.
To get the new version (2.0), go to http://google.com/gmm on your mobile device. It's still in beta, so don't expect it to be flawless.
At this time, My Location (beta) is available for these devices:
* BlackBerry devices
* Some recent Motorola devices
* Some recent Sony Ericsson devices
* Many Windows Mobile devices
* Nokia Series 60 3rd Edition devices
If you have a Java-enabled (J2ME) device, BlackBerry or Windows Mobile device, you can easily check whether or not My Location (beta) is available. Just to go "Help" > "About" from the application. If the box contains "myl: N/A," it means your device isn't reporting a cell.