He just came and cleaned up our house today. He knows his stuff, was up front, honest and quoted a fair price - in fact he was more than fair. He gave us a ballpark figure on the phone after he got a feel for the project, but when he came to the house he lowered the fee our return air and dryer vent was brand new. Later on when he found a problem where the supply vent tied into the AC unit, he fixed it for no extra charge.
The best recommendation I can say is that I am now trying to get my parents hire him to come clean their ducts!