Dozens of websites that permit people to rate, review, spin or flame their doctors have sprung up and operate in much the same way as online services that help people find the best hotels or avoid plumbers who overcharge. Patients and site operators say the trend is good for consumers and good for healthcare because good doctors will provide better customer service because of the feedback, and the bad ones will be exposed. But many doctors say the results are skewed by disgruntled patients and are thus unfair, pushing some doctors to near-ruin after a single post.