Hi red, thanks for the great ideas.

Hmm, I read about how a coax design can use differential rotation speed
between the 2 rotors for the purpose of turning the aircraft. That'd be
pretty easy to do with a wheelmotor for each rotor.

Here's a link to a new kind of wheelmotor which is attracting
attention:

http://www.wavecrestlabs.com

The company is headed by General Wesley Clark, former NATO commander.
Regarding portable fuel cell for propulsion, here's another link:

http://www.intelligent-energy.com/in...6&artID=3 709

And hydrogen is a lightweight fuel too, for lower fuel load.
But suppose you want some extra juice sometimes, for more
maneuvering/lifting power. Then use the new Toshiba battery:

http://www.dpreview.com/news/0503/05...sh1minbatt.asp

It can apparently discharge and absorb energy at a very high rate. This
might be useful for using regenerative braking to recover energy from
your rotor when you're reducing airspeed/altitude, since a wheelmotor
can convert torque/rpm back into electricity. Once you've landed,
regenerative braking would allow you to quickly bring the rotors to a
stop while recovering energy from them.

I'd also imagine the electric motors would be quieter too, so your
eardrums don't take a beating.