World is Not Enough, The (007) - Helicopter Chainsaw Scene
Go to the Helicopter Chainsaw Scene and keep your eye on the set of round blades hanging from the helicopter. Maybe it's just me, but I could swear there are a few shots where the blades aren't even spinning, yet the sound is being made. This seems to be a recurring theme in movie chainsaws.
If the film in the movie camera is moving faster than the blades, sometimes the blades look like they are not spinning, or spinning in reverse. Look for this in movies with horse-drawn carriages or car chases.