In what may be a first, the Great River Region Library system of Minnesota and other public libraries have begun offering free audiobook downloads to their patrons. Currently 700 titles are available and 30 new titles will be added each month.
The audiobooks come from Recorded Books and are licensed to libraries by NetLibrary. Even if you don't have a NetLibrary account, you can still browse the audiobook collection.
Unfortunately the DRM protection technology NetLibrary uses isn't compatible with the Apple iPod. It does, however, work with Microsoft WMA-compatible devices, which includes just about every modern MP3 player except the iPod.
If you don't have a NetLibrary account, check your local library's website. If they're a NetLibrary member, you can probably login or create your own NetLibrary account through their website.
Once you're logged into NetLibrary, you can either download CD or radio quality copies of the audiobook. Once downloaded, the files will be accessible for 21 days, but you can renew them once.
Note that even though your public library may be a member of the NetLibrary system, you may not have access to the audiobooks. If that's the case for you, contact your library directly and encourage them to subscribe to the audiobook plan.