The premise is simple: A group of people from around the globe all pledge to wear only six items of clothing for one month—June 21 to July 21—and document their experiences on a blog. The project is open to anyone, and so far has drawn commitments from around the globe (30 at last count).
You can read what motivated the creators of this project here, but the participants generally fall into four camps: anti-consumerists, the "freedom that comes with a uniform" proponents, creative types ("let's see how inventive I can be with this limitation"), and masochists.