Here is the deal, if you already use your debit card to buy gas, here is a way to make save at the pump.
Sign up for the QUICKTRIP Debit Card. It links to your debit card and for the first 90 days you save 10 cents a gallon. That is IF you activate before 11/30/10. Then after 90 days its 2 cents off per gallon.
Here is a link to the Quicktrip signup site.
Thanks to Teryl for that tip!
This offer really comes down to fees. As I understand it, it costs more for stores in processing fees when you use the CREDIT instead of debit. So this makes sense for them to change customer habits.