How can I get the CLSID for a given interface within a Primary Interop Assembly? Here's what I'm talking about:

// The c# compiler does some interesting magic.
// The following code ...
var app = new Microsoft.Office.Interop.Outlook.Application();

// ... is compiled like so (disassembled with Reflector):
var app =((Microsoft.Office.Interop.Outlook.Application)
  Activator.CreateInstance(Type.GetTypeFromCLSID(new Guid("0006F03A-0000-0000-C000-000000000046"))));

Microsoft.Office.Interop.Outlook.Application is an interface, and therefore it cannot be instantiated directly. What's interesting here is that c# lets you treat these COM interfaces as if there where classes that you can instantiate with the new keyword.

What I want to know is, given the System.Type for a given interface, how can I get the CLSID?

Note: I ultimately want to be able to create an instance given the interface's System.Type - I don't really care how. I'm assuming here that the easiest way to do this would be to get CLSID given the Type, just as the c# compiler does.