Student's push to make Raleigh more walkable relies on homemade signs and QR codes -- Engadget

via engadget.com

QR Codes on public signs are great for guiding and providing information to residents and tourists alike.

Another great use case is putting QR Codes on trails/parks so that visitors can store an area map and emergency contact information on their phones. Here is code from last year:
http://goo.gl/29B1Z