Helicopter design has to be the most frustrating endeavor. Everything you try to do is counteracted by an opposing force.
The McDouglas/Boeing NOTAR light helicopter has been around quite awhile now. Don't know how successful it is. Rather than a tail rotor, it ports engine exhaust into the tail boom, where it is directed at 90 degrees to the boom. It might be on wiki.
Saw a video demo of a heli recently that has counterrotating rotors and a large prop on the tail to provide forward thrust. It looked good.
Boeing has bought a company that has developed a UAV heli. It has conventional rotors. It's called the A160.
GB