Feel a compelling urge to let the world know where you are at all times? Google has you covered. The search giant just launched a mobile app, dubbed Latitude, that lets users share their location with close contacts based on the coordinates of their cell phone (via GPS or cell tower triangulation). Latitude is built into Google Maps and essentially what it does is broadcast signed-in users' locations and give quick access to SMS, instant messaging, or phone calls once they are spotted on the service.

This may sound like a nightmare for privacy-conscious users, but Latitude is of course an entirely opt-in service and gives users complete control over what they are sharing and with whom. If you need to go into stealth mode, for instance, you can just stop sharing your location with all or select contacts and if you wish to tell someone, say, a little white lie about your true whereabouts you can manually set your location to any place on the map.

The company says Latitude is currently available in 27 countries on a number of devices, including Blackberries, Windows Mobile, and Nokia S60s. Android support will begin rolling out over the next week, and an iPhone app is coming soon. The service can also be used on PCs using an embedded iGoogle widget.