Richard Branson has been extolling the virtues of a return to supersonic air travel by backing a new prototype, 'Boom', that could offer a 3.5 hour return flight from London to New York for a cool $5,000.

From an innovation perspective, this looks to be an exciting project - whether it actually gets off the ground (no pun intended) is another matter entirely of course. 

However, I can image the demand for tickets would be huge for such an exclusive, premium method of transport.

I'd still want free champagne though...