A supersonic Harrier...
Just think, if we'd continued with the P1154 Mach 2 Hawker Harrier that was scrapped in 1964 despite work being in progress on the prototype's wings and fuselage and six engines constructed, we could have had an equally capable VSTOL aircraft half a century ago. Don't you just love politicians...
http://www.harrier.org.uk/history/history_p1154.htm
Biting the hand that feeds IT
