Check with your bank and see if they have a rewards program for its debit cards....mine does!
My bank, Wachovia, has a free rewards program for it's debit cards called Wachovia Possibilities Rewards. It's a point system like Target, you get a certain number of points for each purchase and then those points add up and you are eligible to "cash them in" for retail gift cards, Visa gift cards, products, etc. Since signing up a couple years ago, I've gotten a few $50 gift cards to Banana Republic...for free...and I'm close to getting another one. And I signed Hubby's card up too...too bad I can't use his points as well for Banana gift cards.
I use my debit card ALL the time so this is the perfect, hassle free way to earn extra money for my shopping habit. :)