This video is of a group that explored something very interesting with regard to identity in real spaces. You can read for yourself the details of their project on the Vimeo page and on the workshop page, but the gist is to ask how the blatant identification systems of virtual worlds might affect the relative anonymity we experience, much of the time, in the real world.
I also really like the materials they chose to use to build their physical identification platforms. The material has an elasticity in its movement that behaves similarly to those displaying identities in virtual worlds like WoW and Second Life.
How much differently, if at all, would you behave if your name was visible for all to see every moment of the day?