Librivox
Librivox.org is a public domain audiobook site / project. Volunteers record themselves reading a variety of (mostly better known / classic) works into mp3 format, so you can download books into your mp3 player and listen.
The quality is dramatically uneven. Some accents make me want to beat someone with a hammer, and the poetry inflection may be similarly off on many recordings--as if someone were reading them who didn't understand them at all.
But I'm enjoying some of it quite a lot. In particular, the incomparable ghost stories of M.R. James (British, professorial, lightly humorous in bits, sedate, understated, sometimes terrifying in a very quiet way) are way up on my queue these days.