Google Latitude allows users to see exactly where their friends are and what they are up to. The program is compatible with certain mobile phones or available on a PC.
To ensure complete privacy, people must specifically sign up for the free program and then choose to share their precise location, the city they are in or nothing at all.
Latitude can pinpoint a user's location through GPS satellite as well as proximity to mobile phone towers and wireless networks. It also permits users to manually set a specific location if they wish to lie about their whereabouts.
Google hopes furthering its mapping technology will lead to location-based advertising revenue. Competitors include Loopt.com, which connects to other services like Twitter and is currently available on more phone models.
One privacy group calls Google Latitude an "unnecessary danger" to security. Read more here...