StumbleUpon plants trees!! From now until May 2nd, for every “thumbs up” on the StumbleUpon Thumb Up for Trees site, SU will sponsor one tree to be planted by Friends of the Forest.

From the page:

Every day millions of StumbleUpon users discover great web sites and give them a “Thumbs-up”. Starting this Earth Day, we want to harness the power of our community and the “Thumbs-up” to plant trees for the National Forest Foundation.

Simply use the StumbleUpon toolbar to thumbs-up this page and, from now through May 2, with every thumbs-up StumbleUpon will plant a tree with help from the National Forest Foundation*. Your thumbs-up means more trees for America’s National Forests and more visibility for this cause. Give a “Thumbs-Up for Trees” and spread the word!