Another one from Dept Dem Des Ltd:
How about a biplane arrangement, with the top wing hinged at the root, so the tip drops down to the bottom wing in the hover, thus gently guiding the downwash out and round the lower wing and as if by magic the drag disappears! All you'd need is a hinge at the root and a couple of lengths of wire at the tip to stop the wing flying up too far when it's generating lift in flight.
I need a darkened room to lie down in and a cold flannel for my forehead. <img src="smile.gif" border="0">