Instead of spending hours unraveling, testing and hanging Christmas lights, in the future I'm going to do what Saks Fifth Avenue has done with their holiday decorations; Hire a bunch of animators and just point a projector at my home.
If you're the type who loves the attention you get from elaborate holiday decorations, and doesn't mind their lawn being trampled by onlookers, you can pull off some pretty amazing and convincing effects this way. At times the Saks Fifth Avenue building looks like it's actually being deconstructed, and the animation has a real sense of depth to it, seemingly extending right into the department store.
Just remember that projectors this powerful have a real thirst for electricity, and unless you've got a nephew studying computer animation, you'll want to set aside a big chunk of your decorating budget for just a few minutes of custom video. [My Modern Metropolis]