The Big Picture is discussing bubbles, and what light economics can shed on them.
The seminal reference on the computational side is this paper by Brian Arthur, where viral inductive expectations among agents with grossly imperfect information cause most of the behavior we've come to know and love in markets, including bubbles.
On the behavioural side, you should check out Vernon Smith, particularly this nice (pdf) intro to experimental economics, as well as Richard Thaler's work, particularly this (pdf) survey article, and, finally, Robert Shiller, and his workshops on behavioural finance.
Enjoy!