[moultano]

http://soundtracker.com/ is what I use for this. He makes binaural nature recordings. They are as effective as white noise at blocking out my surroundings, but because of the feeling of space and the variety of sound, I don't get tired of listening to them the way I do listening to noise.

Here's an article on his search for quiet places and the movement to preserve them. http://www.orionmagazine.org/index.php/articles/article/3627