Moving from ASP.NET 1.1 to 2.0? Check out Web Application Projects.

The directory-based web site model in ASP.NET 2.0 is pretty slick and I like it, but it isn't for everyone.  If you're used to having a project file to manage the project contents and references, moving to the "everything in the directory is in the project" model may be disconcerting.  The ASP.NET team has released Web Application Projects to extend VS2005 and provide the ASP.NET project model you're used to in VS.NET 2003.  Here is the release announcement from Scott Guthrie's blog:

http://weblogs.asp.net/scottgu/archive/2006/05/08/445742.aspx

I've used is to both help clients migrating from VS.NET 2003 and for clients wanting easier control of their build process.  Since the Web Application Projects as MSBuild compliant, it is easy to get them working under Visual Studio Team System and Team Build!