I know that the Parrot AR.Drone is a quad helicopter and not a true single or coaxial blade helo but from what I see it looks pretty cool. Way more expensive though but not as much as for a full blown RC helo and easier to fly. Folks are modding them to hold GoPro HD cams to get some great video. Check the link to see what one videographer has done to the AR.Drone.
AR Drone / GoPro DIY Aerial Video Mods - RC Quadcopter on Vimeo