But there are lots of books read by podcast now and not just sci-fi. PodioBooks has a very large selection of free and donationware books for you to download and listen to on your phone.
And be sure to check out:
OpenCulture: Audiobook Podcast Collection
LibriVox – Audio books in the public domain
Free books has several free audio books, plus several courses of study
Naxos Audio Books
You have a library in your pocket