I love using Nature SDS for the iPhone and was looking for a Mac alternative and found this gem. It's free and the site has a few samples as well, which should be enough for most. Basically, if you're tired of music and want more natural and soothing sounds, just run one of the files and enjoy anything from birds chirping to a calm thunderstorm. Very relaxing and refreshing while working or kicking back and doing some rss reading. http://projects.gerryscuppatea.org/NaturalWorlds/
