Ok, I must be doing something wrong. In my Droid settings for My Location I have both wifi and GPS disabled. I then go into Google Maps, open the menu, and click on "My Location". I get a message that says "Please enable a My Location source in system settings". How do I get Google Maps to find my location like you all are doing via the cell signal?
EDIT: Ahh, nevermind. "Wireless Networks" under the My Locations setting doesn't mean Wifi does it? Duh.
From my experience with a Droid it can locate by tower location, wifi location database (like Skyhook but Google's implementation), and GPS. Location accuracy seems to be on the order of miles for tower, 100's of feet for wifi and 10's of feet for GPS. I have never seen it triangulate towers - it always centers on a specific tower.
