I actually disagree with most of you guys...I think ratemyprofessors is an extremely valuable asset. Not necessarily for finding out which teacher is "good" or "bad", but it's excellent for ferreting out whether a teeacher is the kind of POS who thinks he/she is god's gift to the world, ridicules students for asking questions, is unhelpful during office hours, etc...
It should be a given that you shouldn't pay attention to the ratings as far as whether the teacher was easy, hard, good or bad, but /why/....if everyone says the teacher is unhelpful during office hours, that probably means he/she is unhelpful during office hours. Likewise if the teacher is a fair grader and everyone says that, same thing. I don't think ratemyprofessors should be used to try to get the easiest teacher possible, however, I think it's a great resource to avoid horrible teachers so you don't get cheated out of your education...I dunno about you but I'm paying over twenty thousand dollars a year for it so I want my damn money's worth.