Want to understand the current economic crisis threatening to blow up the civilized world as we know it? Two very well produced This American Life episodes can help.
By now, everybody knows that the catalyst was the sub-prime mortgage meltdown. To understand that, listen to The Giant Pool of Money.
Once you've gotten your head around sub-prime, continue on to Another Frightening Show About the Economy. (This is the better of the two shows in my opinion.)
In return for a two-hour time investment, you should get a pretty good understanding of how we got here.