Jumping into this thread late ... but you could also use a product like Molebox to statically link DLL/FLL's into a single EXE that gets signed by digital signature that is checked when the EXE starts up.

Note: MoleBox is a great product (highly recommended) but it is currently not compatible with DLL/FLL's compiled with VS Studio 2005. If you're going to use the technique I described above, you need to make sure you are using the VS 2003 builds (MSCVR71.DLL runtime) of Craig's FLL's.

Malcolm