I love this radio series, it really is great. You can get it over iTunes as well. They have a season 4 in the works right now, and seasons 1-3 are all pretty much intellectual candy.

The episode on "Emergence" will be of interest to people here as it pertains to wisdom of crowds/group think/etc. All together an amazing radio series.

Note that they also have seasons 2 - http://www.wnyc.org/shows/radiolab/season2_2006.html and season 3 - http://www.wnyc.org/shows/radiolab/upcoming.html