Ars Technica has written an excellent article about the difficulties of determining good science from pseudo-science in the internet age. I recommend that everyone go and read it, it's excellent. Here's a sample:

The importance of quality information was driven home by a recent study that revealed a tendency for false or misleading information regarding breast cancer to appear on web sites devoted to alternative medicine. So, how is the public supposed to identify quality scientific information? The recent American Association for the Advancement of Science meeting included a session devoted to understanding how the public receives and evaluates scientific information.