The first flying automobile, equally at home in the sky or on the road, is scheduled to take to the air next month. If it survives its first test flight, the Terrafugia Transition, which can transform itself from a two-seater road car to a plane in 15 seconds, is expected to land in showrooms in about 18 months' time. Terrafugia claims it will be able to fly up to 500 miles on a single tank of unleaded petrol at a cruising speed of 115mph. Even at $200,000 per automobile, they have already received 40 orders."
Something like this probably wont ever be mainstream, not after that latest oil shock. Still is pretty cool though.