I was going through articles by ScottGu and came across the following links to Google Map in ASP.Net. The first link is publicized by Scott himself and remaining links are from comments by various users on his site. I have not gone through these links but just publishing the repository in case I or someone else needs it in future.
describes how to build and use an ASP.NET Server Control that makes Google Map integration easy within ASP.NET applications.
http://pietschsoft.com/product/ve3 - Open Source ASP.NET Virtual Earth mapping control
http://stephenjohnstone.com/blog/?p=24 - Open Source ASP.NET Virtual Earth mapping control