I was directed to a great site a while back by the guys at SGU, or the Skeptic's Guide to the Universe.  It's a podcast produced by a neurologist, Dr. Steven Novella, and a few other folks of like mind, Bob, Even, Rebecca, and Jay.  I think the SGU was the first time I was intorduced to people who really took a joy in critical thinking, as opposed to people who used or pretended to use it to get through their day.

I learned that you can get a lot better at critical thinking with practice, which is what they encourage everyone to do.  At any rate, I've listened to every episode they produced except the last few, which are queued up on my Zune. 

The site that I was directed to was www.whatstheharm.net.  We all know people who take their religions to extremes, their herbal medicines to extremes, their Eastern enthusiast's advice to extremes, their belief in the afterlife, ghosts, vitamins, vaccines, exorcisms, astrology, whatever.  Most of us shrug it off with "It's not hurting anybody, just let them be happy." 

The premise of the site is that these things can and, in fact, DO hurt and sometimes kill people.  It's definately worth a quick perusing to see if any of your pet beliefs are on the list and see what happens when people get carried away with it.