Wally has put up some new podcasts around using Google maps and virtual earth with ASP.NET AJAX.
You can check em out at the following links:
Integrating ASP.NET AJAX with Google Maps.
ASP.NET AJAX with Virtual Earth
These podcasts allow you to explore mapping possibilities with the 2 popular mapping services currently available. in combination with ASP.NET AJAX.
Check em out and get geographical !