Divx discs are sold for $4.50, about the cost of renting a DVD. But unlike DVD rentals, they aren't returned to the store. The first time you slide a Divx movie into a player, the device reads the serial number, unlocks the code and starts a 48-hour clock. Whether you watch the movie straight through or hit pause or stop, the clock keeps ticking. At the end of the 48 hours, you can buy another two days for about $3.25 or unlock the disc permanently for $15 or $20 -- the same price range for a standard DVD. You use the remote with onscreen instructions to place the order and agree to the charges, which are reported when the Divx player calls in on a toll-free number. These charges appear on your next credit-card bill. When you're done with the movie, you can put it in a drawer until you want to watch it again, give it to a friend who has a Divx player or drop it in a recycling bin (Circuit City is trying this out). Sure, you could throw it away -- but you'd just be generating unnecessary trash, litterbug.

For anyone of average intelligence, Divx technology is not difficult to grasp or use. But according to market analyst Mark Hardie of Forrester Research, it has a fundamental flaw that is likely to lead to its demise: Divx demands that consumers change their behavior, altering a habit that has become part of the home-entertainment migratory pattern for two decades: go to the video store, rent a movie, then return it. Divx asks them to abandon this in exchange for something more complicated, Hardie says. "Any new way to rent has to be simple," he argues. If it involves phone lines, it isn't simple.

The phone connection opens up another potentially fatal flaw in Divx technology: lack of privacy. Consumers might be uncomfortable with the idea of a home appliance making calls in the middle of the night. While this may be no more invasive than a savings card from your local grocery store reporting your affinity for Raisin Bran at the checkout counter so the supermarket knows to give you the next Kellogg's coupon, it could spook some potential users.