Spurlock recommends (http://lesswrong.com/lw/7e5/the_cognitive_science_of_rationality/4tf9) incorporating the something like the following into the intro on the homepage: Long before the first Concorde supersonic jet was completed, the British and French governments developing it realized it would lose money. But they continued to develop the jet when they should have cut their losses, because they felt they had "invested too much to quit"1 (sunk cost fallacy2).
John tested positive for an extremely rare but fatal disease, using a test that is accurate 80% of the time. John didn't have health insurance, and the only available treatment — which his doctor recommended — was very expensive. John agreed to the treatment, his retirement fund was drained to nothing, and during the treatment it was discovered that John did not have the rare disease after all. Later, a statistician explained to John that because the disease is so rare, the chance that he had had the disease even given the positive test was less than one in a million. But neither John's brain nor his doctor's brain had computed this correctly (base rate neglect).
Mary gave money to a charity to save lives in the developing world. Unfortunately, she gave to a charity that saves lives at a cost of $100,000 per life instead of one that saves lives at 1/10th that cost, because the less efficient charity used a vivid picture of a starving child on its advertising, and our brains respond more to single, identifiable victims than to large numbers of victims (identifiability effect3 and scope insensitivity4).