Some more open-source GIS links, a tool to publish from ESRI’s ArcGIS to Google Earth or MS Virtual Earth as well as a little tool for Mac OS X that automatically switches your network location:
Arc2Earth was created to convert and publish your ArcGIS data to view in Google Earth, Google Maps or Virtual Earth with a click of a button.
The User-friendly Desktop Internet GIS (uDig) is both a GeoSpatial application and a platform through which developers can create new, derived applications. uDig is a core element in an internet aware Geographic Information System.
Mac OS X network location:
Automatic location switching for Mac OS X.