Dowsing, astrology, homeopathy, whenever anything like this comes up I always find it scary to see the angry response that comes from "science" people. It's as if they feel threatened somehow like their gods had been insulted. If they truly thought the subject was worthless they would just ignore it and not even bother to get into the debate.
When I worked in an IT company in Johannesburg one of the kernel developers there used to get extra money finding water for farmers. Not sticks or wands, what he did was get a brick and stand it upright on the palm of his hand. He would walk around and interpret the water course according to the brick's movements. I have no idea how or why it worked but he was getting paid regularly.