This is a bit more complicated than that, DWS.
They are stored...nowhere, AFAIK.
Without a project file for web projects in ASP.NET 2.0, there is no way to register
referenced assemblies other than adding the assemblies to the web project's Bin folder
- which is what a web project's "Add Reference" applet does.
This has been criticicized very much.
When you have a solution with a web project and a couple of class libraries,
new versions of those class library assemblies are copied to the web project's
Bin folder each time they are built.
With multiple people on the team building the solution, they will constantly get check-in
conflicts in the web project's Bin folder because they are constantly creating new versions
of the assemblies in the Bin folder with each build in their own dev environments.
The work around is to not put the web project's Bin folder under source control and to add
a post build event to every project "referenced" by the web project to "push" the complied
class libraries to the web project's Bin folder.
This allows the web project to have the right assembly references and to keep the
source control mechanism from having to play a part in the web project references.
This was supposed to be fixed by RTM by having the references stored in the solution file.
Apparently, it didn't make it to RTM.