We've just approved an Eagle Scout project that includes placement of QR's on existing signs and kiosks within our nature preserve and a website with supporting data ranging from location/mapping to interpretive material regarding the flora and fauna. It's a great value-added feature for the reality of a world where many people are more skilled and eager with their smart-phones that they are with a paper map. It also allows us to minimize the production of paper maps that often wind up "in" the preserve rather than one's pocket.
There were those opposed to the idea, either on the grounds that they are fearful and offended by technology and representations of it, or that they were concerned such things serve people they don't want to be out in the outdoors anyway (or at least, "their outdoors). My view, from the perspective of one who dislikes signs other than trail markers, is that these small graphic images aren't an imposition when placed on existing signeage and have great utility to folks that can use it.
And to those who despise technology, I encourage you to move forward with a "Bludgeon the iTards" campaign. All wearers of earphones in the outdoors must be savagely punished, if only to set an example for the others. Yes, even if they're using a UL iPod and cute, lightweight gear, this blight of self-absorbed, oblivious goofballs must be eradicated like polio or zombie virus. Actually, come to think of it, it may be zombie virus.