I've seen many videos of mini-quadrotor helicopters and they seem to be the most stable and most maneuverable of small-scale hovering aircraft. So my question is why all the toy helicopters in shops are shaped like actual helicopters and are so hard to control when we have something so much better.
Mokalus of Borg
PS - The most popular retail quadrotor available seems to be the "Draganflyer" which is for aerial photography.
PPS - Other than that, it's build-it-yourself instructions.