Google offers location services to Web sites

Google announced two services Thursday that programmers can use to build services into Web sites that employ a site user's location.

The first is a tool for Web sites built with the Ajax programming method. The Ajax client location property provides Web sites with a rough estimate of a user's location based on his or Internet Protocol address, said Google engineer Steve Block on the Google Code blog. The property can be seen in action in the "news by state" feature on Google's 2008 election site API (application programming interface).

Second is an expected change to endow Google's Gears software with the ability to employ more detailed location information. This Geolocation API is only available to browsers with the Gears plug-in installed; Gears enables a variety of features such as offline browsing that make browsers a better foundation for rich Web applications.

"On mobile devices with Gears installed, the Geolocation API can use the cell-ID of nearby cell towers or on-board GPS (if either is available) to improve the position fix. In the near future, we'll be adding data from your Wi-Fi connection to improve accuracy even further, on both desktop and mobile," Block said.

Not everybody wants Google to know where they are, though, and Google says the Geolocation API takes this into account.

"The privacy of users' location information is extremely important. The first time your site calls the Geolocation API to request a user's location, that user will be shown a permissions dialog where they can choose to allow or deny your site access," Block said. "Users can change that decision at any time via the 'Gears settings' dialog in the browser menu. Google does not keep location information about users when your site uses the Geolocation API."