The research division of my architecture firm is exploring new methods of observation and understanding how users interact with the built environment. I know interaction design is generally virtually/digitally based rather than physically, but I thought I'd start a thread anyways. We're looking for digital tools for behavioral mapping that allow us to visually report on how visitors use the space we have designed. We're initially thinking along the lines of time lapse photography or GPS/GIS technology (although for observation within a building). Does anyone have any recommendations of methods, tools or technologies that would help?