Joe Miller’s start-up Print A Forest promises to plant a tree for every 100 pages a user prints. A free application places a branded footnote from sponsors in the unused bottom page margins of the pages that a user prints. A portion of the sponsorship revenue is then donated to the Plant A Billion Trees campaign, which plants 1 tree for every dollar.

The application also tracks your stats so you know how many trees you’ve planted with your printing. By participating, for every 1 tree that is harvested, the donations from Print A Forest will plant 75 in its place. Here’s a video explaining more about the project:

Print A Forest