I recently bought some vampire fangs, but not just any fangs, the ones you mold to your teeth. After, what, four tries, I finally did it and they are great. I tested them out last night, a week before Halloween, and they seemed okay. At first it was a bit weird and uncomfortable, but after awhile you kinda get used to the longer sharp teeth.
The greatest thing was when someone asked me if they were my real teeth because they looked like they were!