Following up on Jason's Tuesday post, which I read and liked. I just got the first issue in a gift subscription to Scientific American. And I have to say, it is a weird magazine. The fringes of current science are way out there!
I, also, have some ideas on why smart people believe weird things.
1) The scientific explanations that "disprove" paranormal phenomena are based on the scientific method and its insistance on replicating events and isolating variables, while the nature of paranormal phenomena is grounded in circumstance, sycnchronicity, and the unique experiential moment. The "objective science" of debunking can't challenge the subjective and experiential nature of the phenomena; it lacks the emotional truth to shake someone's belief.
2) Science itself is, in fact, very weird.
Very weird, very legitmate science includes:
nonlocality - things don't actually have to be near each other to interact (flash demo here);
string theory (a multi-demensional explanation for the nature matter);
and the whole commonly accepted idea that all the matter of the universe was compresses into once place billions of years ago and exploded from that one point and has been moving out from there ever since - you know, the big bang idea.
All of these ideas have logical and emperical facts backing them up and great scientific validity, but all are way out there from the ways we think about our world during everyday life.