Rating Professors

Websites where students can rate professors on items such as helpfulness, easiness, and hotness are controversial among professors yet students flock to them for information before they register for classes. This essay from the Chronicle of Higher Education discusses a professor's experience with the site - and how he moved from coveting a yellow smiley face to a blue frowny face. Another article discusses the issue of fake reviews. What do you think of RateMyProfessor.com?
Also see: College Teaching