In my earlier Deception, Misdirection and Natalie Imbruglia post I discussed my interest in how the mind is easily deceived and controlled. This year I've become intrigued by the research of Dan Ariely (wikipedia). It turns out humans are predictably irrational, baring little resemblance to the rational beings standard economists like to think we are. His book Predictably Irrational is a great read.
Here is an entertaining speech Ariely gave in Dec 2008.