In a sneak preview Thursday, Google revealed how it plans to integrate its AdSense advertising platform with Google Maps, meaning some push-pin graphics used at the maps site could be turned into mini-advertisements.

Google has not set a time frame for when the feature will be ready to go public, said Andrew Eland, a Google software developer based in Zurich who gave a presentation at Google's Developer Day in London.

Eland spoke of the feature during a talk about Google's new "Mapplets" feature, which lets Web developers display content and build applications within Google Maps.

A Mapplet uses two APIs -- Gadgets and Maps APIs. Mapplets can be used show content, such as a description of a building or landmark, and a specific photo and display those in a pop-up window when a push-pin graphic is passed over on Maps.

Around those customized locations on the map, other paid-for points could be marked. Eland showed an example of a hotel advertisement that had its own icon rather than a push-pin.

When the icon is passed over, information appears in the pop-up window. If the link is followed by a user on the Mapplet, "you receive a share of the revenue," giving Web site developers another way to make money for their sites, Eland said.

Users would be able to set a limit on the number of sponsored ads on their customized map and also turn the feature off, Eland said.

"This is something you will completely control," he said.

Google's AdSense program, where Web site publishers display targeted text ads related to the content on their site, has underpinned much of the company's phenomenal increases in revenue.