Blog Action Day:

"On October 15th – Blog Action Day, bloggers around the web will unite to put a single important issue on everyone’s mind.

In its inaugural year, Blog Action Day will be co-ordinating bloggers to tackle the issue of the environment.

What Each Blogger Will Do

Bloggers can participate on Blog Action Day in one of two ways:

1. Publish a post on their blog which relates to an issue of their own choice pertaining to the environment.

   . . . Our aim is not to promote one particular viewpoint, only to
   push the issue to the table for discussion.

2. Commit to donating their day’s advertising earnings to an
   environmental charity of their choice. There is a list of "official"
   Blog Action Day charities on the site, however bloggers are also free
   to choose an alternate environmental charity to donate to if they wish.

And that’s it."