***EASY SPECIAL OFFER***
Plink
It's on several SO walls - SR for 236, PW for 270, PL for 233 and some say on SP for 270 but I don't see it there.
I did it on SR for 236sbs. It wants you to link a credit card to the Plink account but an old Walmart or Starbucks gift card will work. I've seen reports of CVS cards working too. I used a Walmart gc that has a small balance on it but once I fill up my gas tank again it will be empty and I'll get a new one.
As I recall (I did it several hours ago) it just required name, email, set up user name & password then select a CC/GC to use. With the Walmart gc you enter the number on the back and then the pin number. Then it asks you for another user name/password (like it wants the one linked to the card you are using) but you can just use the one you set up for the Plink account.
You do need to confirm the link in your email.
Many reporting completing this offer on all walls with the same gc if you use a different email on each one. I've only done the one. Will try another tomorrow and see what happens.