It was pretty funny, but my favorite online parody was the Rocky and Bullwinkle Horror Picture show. Wish I had the address...
Anyway, I once wrote a parody of Rocky Horror with Inspector Gadget. Dr. Frank N Furter was a MAD agent.
My favorite songs on that would have to be, "Let's do the Gender warp again," and the Stage show song "Penny and Brain."
If anyone wants a summary or lyrics, ask me, and I'll E-mail them to you!