Offline Tangible User Interface

When shopping for a sofa I used an interesting tangible user interface - magnetic stickers. For each of the sofas systems the customer can create their own configuration using these magnetic stickers on a background (everything in a scale 1:50).

After the user is happy with the configuration the shop assistant makes a xerox copy (I said I do not need a black and white copy I make my own color copy with the phone) and calculates the price and writes up an order. The interaction with the pieces is very good and also great as a shared interface - much nicer than comparable systems that are screen based. I could imaging with a bit of effort one could create a phone application that scans the customer design, calculates the prices, and provides a rendered image of the configuration - with the chosen color (in our case green ;-). Could be an interesting student project…