Googlemaps My location w/o GPS or WiFi

[snipper_cr]

I was reading that google maps can determine your location based on cell phone towers (according to the google maps development blog), similarly to how E911 gets your location.

However, when I turn GPS off and WiFi off, I get the "Your location is not available." Is there a setting I have to turn on (like GPS location?) to get it to show my location? I know its quite inaccurate but it's something I'd like to use.

Thanks.