Google Latitude

Google Latitude is a location-aware mobile app developed by Google. Latitude allows a mobile phone user to allow certain other people on his or her Gmail contact list to track where he or she is. These people can track the user (or more accurately, his or her phone) on Google Maps via their own iGoogle accounts. The user can control the accuracy and details of what each of the other users can see — an exact location can be allowed, or it can be limited to identifying the city only. For privacy, it can also be turned off by the user, or a location can be manually entered. The user must enable the location features of the phone, which are normally only transmitted to emergency telephone numbers such as wireless E911.

Google's 2005 acquisition, Dodgeball, offered similar facility to users by way of SMS. With Google Latitude, the service has expanded to PCs (it uses IP geolocation as well as user driven input) and automated location detection on mobile phones using Cell-ID, Cellular Positioning, and GPS.

Privacy concerns
Amid concerns over locational privacy, Google announced that Latitude overwrites a user's previous location with the new location data, and does not keep logs of locations provided to the service.

Compatibility
Google Latitude is compatible with most devices running Google Android, BlackBerry OS, Windows Mobile, or Symbian s60. Compatibility with iPhone, and iPod Touch devices is also planned.