A simple table can be a profound tool for collaboration, so it's particularly disappointing that we haven't yet solved the puzzle of how to effectively digitize that experience. Microsoft's original Surface table was cool, but expensive, and newer options like Lenovo's Horizon PC still haven't taken off. But Tokyo-based design firm Takram has one idea that might help us achieve interactive digital tables (and other surfaces): Just use paper. Last year it developed a concept called "On the Fly Paper" for Intel's Collaboration Center in Japan, which uses an infrared sensor and specially formatted pieces of paper to manipulate a projected computer display. Basically, the paper acts as an input device: As soon as you place it on the table, the projected image changes both on the table and the paper itself. You can also manipulate things by moving the paper around and covering physical holes. What's truly remarkable is that your interactions with it register almost as quickly as a touch screen. Check out a brief demonstration below.