Librivox offers free public domain audiobooks, available for download in MP3 or OGG format. This collaborative project boasts an impressive selection of fiction, poetry, non-fiction, and drama. Good for the commute– you can download one of those classics that you always meant to get around to read.
If you’re looking for a bit of early-morning cheer on a chilly winter morning, I’d recommend My Man Jeeves or Right Ho, Jeeves, both by P. G. Wodehouse. If you’re feeling slightly more ambitious, there’s always The Canterbury Tales (War and Peace is still in progress).