Terrafugia TransitionThere have been more than a few promises of 'flying cars' bounding around over the last few years, what with Moller's Skycar and the odd Google Earth illusion.

But none have seemed quite so sleek and practical as the Transition. Billed as more of a 'roadable aircraft' than a flying car, it has wings which one would simply fold up for road use.

Not 'if' but 'how'

29-year-old Terrafugia CEO Carl Dietrich has all but raised $3m for developing his award-winning design, and suggests a drivable prototype may be on the roads and in the skies by 2008. The real question is, will we be able to take off from the middle lane on the M42, or will we need to make our way to an airport to get in the air?