Dave, your magic carpet already exists:
http://jnaudin.free.fr/lifters/main.htm
These work by ionising the air then using the electric field to create induced flow. At some point these guys will stop wasting time with triangle shapes and just go for a compact grid. Best if the wires are aerofoil shaped too, to minimise parasitic drag on the induced flow.
This technology might approach the helicopter for payload capability.
Slowrotor, you are absolutely right that the key to any of this is too minimise the mass for a given lift. Helicopter currently wins hands down over Coanda effect or ducted fan designs. If you include the main gearbox and anti-torque device then wings have better performance.
Still, good to think outside the box.