Check out this interesting site called Change.org. Here is a blurb about their vision:
Today as citizens of the world, we face a daunting array of social and environmental problems ranging from health care and education to global warming and economic inequality. For each of these issues, whether local or global in scope, there are millions of people who care passionately about working for change but lack the information and opportunities necessary to translate their interest into effective action.
Change.org aims to address this need by serving as the central platform informing and empowering movements for social change around the most important issues of our time.
I’m just starting to explore the site myself but thought I’d pass along the info. If you sign up, you can add me as a friend. I’ll probably have more to say about this site as I figure it all out, although I’ll most likely share the information on my new blog.