For a limited time, you can get a $10 statement credit for spending at least $10 at a local small business when you pay with your American Express card and check in via foursquare, the social networking site that allows you to share your location with friends.

From foursquare’s blog:

Check in at a merchant with a Special… load the Special to your card, and then pay for your over $10 purchase with your American Express ® Card. No need to show your phone to a cashier or anything – you’ll receive the credit on your Amex statement within 5 business days.

To participate in this promo, you’ll need a smartphone or mobile device with Foursquare.

If you don’t already have the foursquare app on your phone, the easiest way to take advantage of this offer is to follow these steps:

• Sign up for foursquare online and download the app here.
• Then, you can sync your Amex with foursquare at sync.americanexpress.com/foursquare/
• Find a participating location by hitting ‘Specials’ on the ‘Explore’ tab on your foursquare app (there are hundreds of thousands of participating businesses)
• Finally, when you are at the participating location, check in using the foursquare app and activate the promotion before using your Amex to pay