You will need to swipe your credit/debit card, but will not be charged unless you return it late (after 9pm the next night). In that case, you'd pay $1/day for each day it's late.
Check here for Redbox locations. You can use each code once per credit/debit card.
Other Current Codes: (as far as I know they're current - let us know in the comments how they work for you!)
DVDATWAG (valid only at Walgreens locations)
DVDKROG (valid only at Kroger locations)
DRIVEIN (valid only at Sonic locations)