Free for MP3 Players and PCs:

Audio Books & Music
Set up an account with your library card and search the Marmot catalog for books and music to download.

Net Library Audio Books
While you are in the library set up an account that you may then use from home to download more audio books.

Free for iPODs:

LibriVox
LibriVox offers thousands of titles in the public domain, read in various languages, available for free download.

Podiobooks
Audio books from authors who have given permission for free downloads.

Openculture
Languages, music and fiction and non-fiction in the public domain are available in podcast form through Openculture.

Low Cost for iPODs:

audible.com
The latest, hottest titles are available for download through audible.com for a small fee. At this time audible is not set up in a way conducive to providing this service through libraries, but you may wish to subscribe on your own.