CBS is testing mobile ads that target users by geographic location, reports The New York Times.

The media company is partnering with Loopt to take advantage of its GPS technology, which allows people to keep track of friends, family and other connections. The GPS system will help feature ads for users of CBS Mobile News and CBS Mobile Sports.

CBS hopes the ads will add value to the mobile experience, which is key to overcoming general dislike of ads on mobile devices. Users must opt-in to the system — a usability decision made to alleviate privacy concerns.

Customers of Sprint Nextel and Boost Mobile will be exposed to the ads, since the two carriers have deals in place to offer Loopt's software. Overall, the two CBS Mobile sites served over five million unique visitors in the last quarter of 2007.

No advertisers have signed on yet but CBS believes national advertisers will be among the first to show interest.