At GolfNow, book one round of golf and get a second round of golf for a friend for free via coupon code "FBBOGO13". (Select your desired location, then click on the "Hot Deals" banner on the right-hand side to book at an eligible course.) That's the best deal we've seen from this service, which allows you to book tee times at golf courses across the country. Some conditions may apply. Deal ends August 31.