In 2010 before a company "Salon" event at Smart Design with sustainability expert Jeffrey Hollender, my colleagues and I decided to come up with a unique way to display our Earth Day pledges. Since we use a lot of LED matrices in our product prototyping work, we thought it would be great to display them in bright lights, but knew that LED displays require energy consumption, and would be counter-productive to the larger sustainability effort. Our solution? Human power! The end result was a two foot wide sign that scrolls through our pledges when a crank is turned.

For more info visit the Earth Day Sign blog post at SmartInteractionLab.com.