I was pretty excited to hear about this. I think its a great Concept.

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

So on October 15th, please blog about the environment, and how it relates to your blog topic.

For example: A blog about money might write about how to save around the home by using environmentally friendly ideas. Similarly a blog about politics might examine what weight environmental policy holds in the political arena.

Learn more: blogactionday.org

on a side note. What a great way to promote a topic. So many of us blog about this anyway. I think this is the first I have ever heard of a blogging rally.