We have a trip planned this summer out to the west coast for 2 months, with the kids meeting us along the way, and Sandy already has food and activities lined up for 50% off or better.
You have to create an account, but it's free. You set up a profile of what items you are interested in:
Then when you find something you want to buy, you will make the purchase on-line with a Credit Card. You pay the discount price, print the certificate, and show up at the store for dinner, or what-ever. We never had a problem with any of the merchants, they were all happy to see us. Groupon is a very legit advertising company, and I'll bet if you ever have any problem you'd be covered.
You just sign-up for cities along your route of travel, or where ever you happen to be hanging your hat, and you'll get emails for Groupon offers.
If you'd like to sign up for groupon, please use this link (I get a kickback). Not that I'm selling anything, I just think it's a good deal for everyone.
There's another company that offers the same type of service, called Living Social. It's another source of savings that we used while in Hawaii and will use again in the future. But, most of our purchases to date have been with Groupon.