Tech Crunch says that the Google’s mobile team has released a Geolocation API for Google Gears.
Google finds a mobile phone’s location for its own mobile apps, such as Google Maps, and is now opening that technology up as an API to outside developers.
The Google Mobile blog shows how these two apps make use of the Gears Geolocation API, which can determine your location using nearby cell-towers or GPS, as well as your laptop’s IP address. Google provides this service for free to both developers and users.
Gears is available on IE Mobile on mobile and Internet Explorer and Firefox on desktop.
To use the location-enabled lastminute.com and Rummble web apps you will need a Windows Mobile device that supports GPS or cell-id lookup (for example the Samsung Blackjack II and HTC Touch Dual, see supported devices FAQ).
There is also more detailed information on the API on the Google Code blog.