October 15 is Blog Action Day, which "brings together bloggers from different countries, interests and languages to blog about one important global topic on the same day. "Last year's theme was water, and previous themes have included environment, poverty, climate change, and food. This year the theme is the Power of We, "a celebration of people working together to make a positive difference in the world, either for their own communities or for people they will never meet half way around he world."

If you're interested in participating, you can register your blog and get more information here.