Currently I have started a new project and I am looking into some geo-related projects. NASA World Wind 1.4 [1] is now available. World wind makes massive usage of .NET and DirectX and runs quite smooth under windows Vista. The data is also provided by Microsoft Research TerraServer-USA [2], hosting aerial photography and topographic maps.
Unfortunately, TerraServer provides only United States Geologically Survey (USGGS) data. Better images for local European location can be accessed using the Virtual Earth plug-in [3], available from [4]. A video of Virtual Earth in World wind can be found at [5]. Unfortunately, the plug-in does not seem to work with the latest World Wind version.
[Update 24/02/2007]
With the updated plug-in for version 1.4 available at [3] also the Virtual Earth data can be displayed.
[1] http://worldwind.arc.nasa.gov/
[2] http://terraserver.microsoft.com/
[3] http://www.worldwindcentral.com/wiki/Add-on:Virtual_Earth
[4] http://www.brains-n-brawn.com/default.aspx?vDir=veworldwind
[5] http://www.youtube.com/watch?v=Oidt5SgfwJw