Here’s one way to bring location-based checkins to the masses — use them to shave off a few dollars at the gas pump…

Murphy USA, a gas station chain with 1,000 locations situated in the parking lots of Walmart and Sam’s Club stores, announced Wednesday that it’s offering $2 off a $20 purchase of gas with aFoursquare checkin. To sweeten the deal, the chain is also offering a free pack of Stride gum. The chain announced the deal on its Twitter feed and Facebook Page.

The offer comes as gas prices have hit $4 a gallon in many areas of the country. And Murphy has been at the forefront of social media marketing in a category not known for such outreach. The chain also has an iPhone app that helps customers locate the stores.

On the other hand, Murphy’s embrace of technology may be causing a rift among its target users: After the deal was announced, many fans on the brand’s Facebook Page are complaining that the Foursquare deal penalizes consumers who don’t have or can’t afford smartphones.