Google Maps developers can now monetize Google Maps API v3 maps with Google Ads.
The new Maps Ad Unit overlays relevant AdSense ads on a map. Developers can control where on the map the ads are placed, and the ads shown are based on the current map location.
To get more help implementing the new Maps Ad Unit view the Google Maps API v3 documentation. The documentation includes a good example that allows you to view the different AdSense units at different positions on a Google Map.
Via: Google Geo Developers Blog