One "VTOL" suacer that got to the preliminary designe stage was this
Focke Wulf "VTOL"
http://www.luft46.com/fw/fwvtol.html

I have no doubt that the device would work and is superior to the tilt
rotor concept and its troublesome gear boxes. It seems to have ducted
a gas turbines' exhaust to power a large contra rotating ducted
propellor in the center of the "saucer" with the tubine then being
deflected to provide forward propulsion.

Indeed if built today it would be excedingly usefull as unlike a
helicopter or tilt rotor it could manouever along side a skysraper or
land in tight spots free of the dangers of rotor impact.

Here's more information on the Fw VTOL:


http://www.germanvtol.com/fwvtolfolder/fockewulf.html

Rob