I've been long interested in the potential of projection in conveying information. While traditional projection is simply images cast onto flat surfaces, projection mapping involves integrating the image with the three-dimensional surfaces it is displayed on. Certainly, it's useful for fantastic visualization:
But surely there are uses that are... useful? I just came across this 2007 project designed by Pentagram that fits the bill perfectly.
The model, developed on the concept of a communal table, creates a shared space where visitors to the center can gather to learn about the history and opportunities of the area. Using a gyro-mouse, users can highlight streets, buildings and other points of interest, receive practical information about local museums, restaurants, shops and neighborhood events, view historic and contemporary photographs or watch short documentary films. These graphics are all seamlessly projected onto the 3-D model from two digital projectors hung from the ceiling.
Pretty great, right? See it in action: