While browsing thru my library's online catalog, I noticed an entry marked "electronic resource". Clicking on it took me to netlibrary.com.
My library has a deal with them. If you sign up in the library you can access selected works from home. It looks like everything has Digital Rights Management on it. Not cool, but understandable at some level.
The selection seems pretty slim for the audio books (which is mainly what I'm after).
All that said, it's still pretty neat. It could be VERY cool if the really expanded the catalog and removed the DRM.