As if twittering birds weren’t a sign of spring, Earth Day is coming up and Brighter Planet has launched a “Tweet-a-Thon” to encourage people to tweet environmental thoughts and maybe win a prize.



Since you’re limited to 140 characters, the tweets are already economically resourceful.

Bright Planet, a Vermont-based environmental startup, is aiming for 2,000 Tweets, and at more than 800, is almost half-way there. One tweeter announced that she had just replaced all her bulbs with compact fluorescent light bulbs (CFLs), and plans to start an apartment compost bin. Another tweeter is planning to walk to work on Earth Day, April 22.

Other environmental groups, such as Treehugger and The Climate Project have signed on to encourage their Twitter followers to share conservation tips, environmental news and Earth Day plans using #earthtweet. And if you’ve really got an inspiring tweets, eco-friendly prizes are being rewarded by partners such as Gaiam, Patagonia and Clif Bar.



In addition to individual efforts, the Tweet-a-Thon offers opportunities for companies doing green things to tweet about them, too.