The Little BIG Things is available as an audio download. At iTunes ($26.95), from Audible.com ($30.61/$7.49 [promo]), and other places we haven't tracked down yet.
Oh, and we're going to put audio files up at tompeters.com. One section a week or so. (There are roughly 40 sections in the book.) The four 'Ways' in the first section are up now.