Remember how I mentioned Redbox last month? For those not in the know, Redbox is a video rental service where you can rent (and even buy) DVDs from a kiosk located at your local supermarket, convenience store, or even certain fast food establishments. What makes Redbox so interesting is that they regularly give out free rental codes. To use the code, you need to insert your credit card into the machine and press a button labeled “Rent with a Promo Code” before entering in the code.
You can get free codes mailed to you by signing up for their online mailing list. You can also get codes by following them on Twitter or by visiting their blog. Also, one of AMM’s friends is also known to give out codes he’s gathered on his Twitter account.
For more information on Redbox and their rental service, I recommend visiting their Wikipedia entry.
UPDATE: You can find even more codes on the DVD Talk forums!