Copied from the NY DEN post from Christine Southard.

Earthcast is a 24-hour Earth Day webcastathon, starting at midnight GMT (or 8:00 pm EST in NY) on April 22, 2009. Teachers, students and people from around the world will speak live on topics about our environment. You can participate too!

Check out the details at http://earthbridges.net .

They’ve even created a VoiceThread for this event. Check it out!