I’ve got to say the barefoot running thing. I know I will be attacked by saying this because a lot of people swear by them. Before you jump on the bandwagon though look at this article by ACE http://www.acefitness.org/certifiednewsarticle/1641/ It really highlights the goods and bad of the shoes. In my opinion, and I may be wrong, but I think people are using the shoes the wrong way.
Next in line would be energy bracelets, I saw a booth for those at the Fitness Fest in Scottsdale. These are a classic example of humans looking for a quick cheep fix. I also have an ACE article to go with this one! http://www.acefitness.org/certifiednewsarticle/1261/
Thanks for reading my two cents!