I've posted at least once in the past about fledgling attempts to create noise-free zones. Aside from noise, humans create another kind of non-noxious pollution - light pollution. The government in Ontario, Canada, has created the world's first sky preserve, a 1,900 hectare area of land where the sky should be free of any kind of pollution from ground-based lighting. Lots more on the same site. There was also a segment on the USA's National Public Radio programme, Living on Earth and here's the transcript. Oh, just realised there's an International Dark-Sky Association. (via FoRK)