Or, to be more precise, a weather website experiment. The US National Weather Service has been looking at new ways of distributing useful weather information over the Internet for awhile now. XML-based data streams are widely used, but even pressure from corporations and Senators hasn't stopped the NWS from trying new ideas. All for free, of course -- this is paid for by US citizen taxes.
The latest experiment involves Google Earth. Google Earth is a standalone software version of the satellite images underlying Google Maps; currently available for Windows, Mac (and Linux?) versions are coming real soon now. The NWS is now making weather forecast data available in the Google Earth plug-in format. Currently, files for maximum and minimum temperatures can be accessed and put into the system. There's little documentation, so it's unclear precisely what area this covers; it may only cover the region around the Tulsa, Oklahoma NWS office.