RC Car-towing 
The idea to this experiment i got from this mailing-list. It was
RC car-towing... First we started with a electric buggy with powered
by 7 cells, 1/2 kg. ballast inside the car, 20 meter towline, and a
Ariel HLG from Voltz, vsp. 1,5 m, weight 420 grams. After
experimenting some starts, we ended up with a line about 50 meters,
and we removed lead from the car as the windspeed was less the second
day. The towing goes wery well, but the car is unable to lift the
plane off the ground, so we have to let it go from our hand. Next try
will be with a longer line (about 100 meters), and the car is now
modified to 10 cells... A most amusing experiment, which gains lots of
applause when the HLG lifts the buggy off the ground, and we can watch
it's struggle to gain ground contact, and continue to accellerate...
As I said: A most amusing experiment! Not wery usefull, but plane and
simple fun...