Most of ChristianAudio's books are on sale for download for $9.49 until 11:59pm PT, December 1, 2008. I'm also finding a number that are apparently free, at least today (The Jesus of Myth and History, by N.T. Wright; Is Jesus Christ Truth for the 21st Century?, by John Stott).
Get 'em while you can!
(Note: correction from my previous "today only")