By Owen Gleiberman
Updated August 29, 2008 at 04:00 AM EDT

Certain topics — the Enron disaster, the industrialization of corn — are so thick with unsexy detail that if you happen to see a good documentary about them, it can produce a kind of catharsis. ”Aha!” you exclaim. ”Now I finally get it!” I.O.U.S.A., a sharp, absorbing portrait of our national debt crisis, has that energizing brain-food effect. The film traces how America, whose federal debt reached $8.7 trillion in 2007, has put its future into hock. It’s a scary, sobering look at toothless leaders and credit-addicted consumers locked in a duet of denial. If they handed out an Academy Award for Most Gripping Graphs and Charts, this film would take it. A