This experiment uses a custom XSLT to convert GeoURL's site-specific "near" information in RSS format to create a Google Earth KML file.
You can create a static list (a snapshot based on the current sites indexed by GeoURL) or a Google Earth network link, which can be refreshed from within the application to get an up-to-date listing. Note that, to conserve bandwidth, this script - which uses my handy PHP feedreader class - caches requested GeoURL RSS feeds for 12 hours
For diagnostic purposes, you can view the actual XML generated by the script. Otherwise, the generated file should automatically be loaded in Google Earth.
N.B.: the script does not currently contain any error handling. If a site is not included in GeoURL's index, the generate KML file will fail without a user friendly warning. Ensure that any site you submit was indeed indexed by GeoURL beforehand.