Zhest!?

The Zehst is a "Zero Emission Hypersonic Transportation" plane. It would take you from London To Sydney in 3.5 hours! What would normally be over a days journey, becomes a comfortable 3.5 hours. The plane goes 3125mph, which is over 4 times the speed of sound, so Mach4. This plane would probably be ready by the year 2050 and do this for us.

Also, the plane is 100% enviromentally friendly, because its biofuels are made from some sort of sea weed. Would this not be awesome? Traveling such long distances in such a short time, visiting family across the world would not be anywhere near as much effort as it is today! But I gues it would be a lot more expensive...
http://www.geekologie.com/2011/06/zhest-hypersonic-plane-to-carry-passenge.php