Amex and social networking site Foursquare recently announced a partnership to offer their users special discounts at selected merchants. Under this system, Foursquare users with an American Express account can sync their accounts together and then receive “check-in” discounts without the need to print or clip a coupon.

For those unfamiliar with Foursquare, a “check-in” is when you tell Foursquare that you are at a particular location, such as a restaurant, store, airport, etc. This information is then broadcast to your friends. In this case, if you’ve also synced your Amex with your Foursquare account, it will also let you know if the merchant is offering a special discount.

To participate in this program, the basic process is this:

1. Register your card at this site to link your American Express card to Foursquare.
2. “Check in” via Foursquare when you get to a restaurant, shop, etc. If there is an Amex special at the merchant, select the promo through Foursquare.
3. Make your purchase as normal with your American Express card. Your discount should be credited in a future statement.

Note that you will need a smartphone or mobile device with Foursquare in order to take advantage of this program.

American Express has announced 3 initial nationwide deals as part of this program: $20 back for a $50 purchase at Sports Authority, $10 back for spending $75 at H&M, and $15 back for spending $100 at restaurants in the Union Square Hospitality Group.

What makes this deal potentially hotter is that since there are no coupons involved in the transaction, you should be able to stack real, paper coupons on top for additional savings.

For more info or to register your accounts, see americanexpress.com/foursquare.