Maybe some of you have heard about this, but Cornell University has compiled a library of nearly 150,000 nature recordings representing approximately 9000 species (primarily birds). The earliest recording dates back to 1929, and the clips come from a variety of media and sources (of course, with varying quality and usability). Certainly inspirational, and some of the recordings are pretty hard to believe — the HAMMERING WALRUS sounds mentioned in a blog post are pretty mind-blowing.
HERE is the libary's home page.
HERE is the link to the blog post.