>From an EXE, I can get the version ID from the interface, such as 1.0.3298.26617. But, for a DLL, such as a DLL for a Web site or a DLL that is included in a Web site project, is there a way to obtain a version ID?

Using reflection you can. Or is it C# only thing? In the C# book I have there was a chapter on reflection that described it, if I recall correctly.