Want to play a video game on a giant digital billboard using your smartphone as a controller to win free food at the nearest McDonald's?

Welcome to the ever-more-creative world of interactive digital signage.

An interactive video game-playing digital billboard that McDonald's set up in Sweden has spurred on blog posts across the Internet, raising the restaurant chain's profile but also shining a light on the interactive possibilities inherent in digital out-of-home advertising.

I first came across it on Mashable, and then on Dave Haynes' 16:9 blog, but a quick Google search turns up enough hits to bring a smile to Grimace's face.

Passersby can enable their smartphones to act as game controllers for a Pong-style game on the billboard, apparently without even downloading an app, and if they can last long enough in the game, they get a coupon for free food at a nearby McDonald's zapped to their phone.

This isn't too dissimilar from another interactive billboard idea, apparently from DDB Stockholm (the same ones who did this new billboard?), that involved snapping photos of images displayed on an animated digital billboard using a smartphone camera, then getting the photographed items for free from a nearby McDonald's.

(DDB Stockholm also were behind the brilliant Volkswagen "Fun Theory" piano stairs video that went viral a couple of years ago — which, if you think about it, was kind of just another form of interactive digital out-of-home, just underfoot as opposed to overhead.)

McDonald's has long been at the head of the class when it comes to inventive marketing initiatives, and if the bright lights of the Golden Arches are lighting the way toward using digital signage to engage customers in more intensive ways, that can only be a good sign for the future of the industry as a whole. Where McDonald's leads, others are surely to follow. And the Golden Arches make for an awfully noticeable landmark.