There are signs along I-4 here in Florida (between Orlando and Tampa) that say that there is aerial surveillance looking for speeders for several years now. Though, there's a picture of a cessna-type plane on the sign, heavily suggesting it's a human pilot :P
Those are real. The pilot times how long it takes you to travel between two lines painted on the road. If it takes too little time, he radios to one of his buddies in a patrol car. You then get a "reward" for being a fast driver.
