Today's code for a free Red Box movie rental is . . . TS473G.
Go rent your movie and just be sure to have it turned back in by 9pm tomorrow. These machines are pretty neat. If you've never used one before, after picking your movie, you push the button that says to use a code. Then you type in your code. It will want an email address too. You do have to scan a credit/debit card but you won't be charged unless you keep the movie extra days. Then it spits out your movie.
When you return it the next day, you push the button that says you're returning a movie, stick it in the slot. It says Thank You and you go about your merry way. When you get home you will have a nice email waiting for you confirming that it was returned.