Due to my focus on US Government customers, I get asked quite a bit about using Bing Maps in environments without internet access.  My response is always to point them to the Microsoft Bing Maps Server:

http://www.vexcel.com/geospatial/bingmapsserver/index.asp

Recently, a 3 part webcast series was delivered diving fairly deep into the Bing Maps Server.  Details here:

http://www.bing.com/community/blogs/maps/archive/2010/02/22/go-offline-with-the-bing-maps-server-web-cast.aspx