Last Updated Oct 3, 2007 2:35 PM EDT
A simple google search will yield these kind of results, but if you want to prod a little deeper, now is your chance. As Craig noted on his blog, he and Jim will be answering questions users post as comments on Freakonomics. Although not all questions will be published, the ones that are already up there are sure to yield insightful responses.
(Craig Newmark image by Whistling in the Dark)