If you're constantly on Twitter (and I know you are), put your tweeting to good use and enter RetailMeNot.com's Twitter contest. All you have to do is tweet a money saving tip and tag #retailmenot. For each money saving tweet, you’ll be entered to win a $500 shopping spree at Macys. RetailMeNot will be giving away one $500 prize each day through the end of July and one $1000 grand prize at the end of the contest for the most original tip. You can enter as many times as you like. For more info on the contest, visit their Twitter page.