Foursquare, the location-based social networking app that debuted at SXSW is heading back to SXSW 2012. And, they want to give you some money.

If you have a Foursquare account and an American Express card (U.S. only), you can sync the two together and get discounts galore when you visit SXSW 2012. Foursquare recommends that you use their app while in Austin, specifically the Explore feature. When you do so, you will be shown the best places in town, based on where you, your friends and Austin’s local experts have been. In the app, you will see deals for American Express card holders marked in orange.

The Foursquare blog tells how to redeem your $10 savings at all the locations you’ll find marked:

Redeeming your $10 is super easy – tap ‘Load to Card’ on the Special screen once you’ve checked in, pay with your American Express® card, and see the $10 credit on your bill in a few days. No need to show your phone to an employee or anything. (If you want to be super prepared, you can sync your card in advance here.)

According to Foursquare, there are thousands of places at which you can redeem a $10 savings.

The American Express Terms and Conditions on the Foursquare program do mention a few more details.

Once you have completed the registration/syncing process, when you use your Foursquare account to “check in” to a location for which an Offer exists, an electronic message will be sent to your mobile device through your Foursquare account notifying you of an available Offer (such as, by way of example, a statement credit or point of sale discount) and you must activate certain Offers by pressing the “Load to Card” or similar button. To redeem an Offer, you must follow the instructions in the Offer Terms and use your Registered Card for the entire purchase described in the Offer at the location described in the Offer, unless otherwise indicated in the Offer Terms.

So, apparently there will be offers sent to your phone via Foursquare, not just orange markers within the app itself.