Last winter term I was teaching a class on Unconventional User Interfaces at the University of Linz as part of the MSc in Pervasive Computing. As part of the exercises the students had to do a project and write a paper on the topic in a group. This required to do a full round in the development (from idea creation to study).
Florian König and his group had an exciting idea for a novel form of advertisement. The user is mirrored in the advert and becomes a part of it. They implemented an interactive poster for a travel agent (users become part of the holyday scene) and tested it in-situ. The paper was accepted at the German HCI conference (Mensch und Computer) and Florian presented it today very well .
In the questions there was much discussion about privacy and user acceptance. We discussed whether or not such a installation would be legal in Germany (people mentioned the Datenschutzgesetz §6).
 Johannes Schönböck, Florian König, Gabriele Kotsis, Dominik Gruber, Emre Zaim, Albrecht Schmidt. MirrorBoard – An Interactive Billboard. Mensch und Computer 2008. Lübeck. Oldenbourg Verlag, 2008, p 207-216.