Google announced a new mapping/mobile feature called My Location. My Location allow you turn your phone, using a browser and Google Maps, into a GPS device – even if it doesn’t have a GPS function.

Not too many phones supported yet, including the iPhone, but this is another big leap for mobile advertising as, if you can just pull your phone out of your pocket and it knows where you are, it can deliver the nearby pizza ad without you doing much of anything. Of course directions, menu, specials and even a personal coupon could all be part of the deal.

The remaining challenge is numbers. How do you get the numbers of users in general locations tied to the ads to make the financial model makes sense for service provider and advertiser alike.

The service uses cell tower signals to approximate your location if you don’t have a GPS enabled phone.