Debugging with source
Mike Taullty has a post on debugging your app's and needing to see source using a combination of debugger and reflector. Although things do differ one approach is to use
Rotor, it really does depend on what your doing as to see if Rotor would be a good choice as a it is a limited sub-set of the .NET Framework after all. Rotor will let you run your app's under it's CLR and you can append a debugger like sos to it (and you can read the source files directly).