You can get loads of free audiobooks here in "okay" quality
http://audiobooksforfree.com/
or pay for better quality recordings of the books available. The site has not been updated since February 2008 but I have had a lot of pleasure listening to their books over the years.
These days I borrow books on CD from the library and download them too. My library (Volusia County, Florida) is blessed with downloadable audio and ebooks. I belonged to audible.com for many years - had two accounts so got 4 books per month - but cancelled my membership when I had gathered a huge backlog to listen to (still working my way through), and spent more time reading ebooks instead. In the meantime I also became a Sudoku fanatic so I tend to do that a lot on flights to pass the time!