Layar is a mobile application that uses geo-location to enable users to interact with Augmented Reality (AR) content. It also allows for vision-based AR as well.
William Denton, the web librarian at York University Libraries is currently experimenting with Layar to develop AR content for York’s Keele Campus in collaboration with the Alternative Campus Tours Project, with the support of the university’s Academic Innovation Fund (AIF) for 2011-2013. You can interact with his project here.