Just wanted to comment on my experience with walking and listening to audio books. It was pretty nice! There were a few times where I had a hard time paying attention to the book, but for the most part it worked pretty well. This might be a breakthrough for me: now I can get some much needed exercise and burn through some books at a good pace! Plus today was beeeaauuuttifulll so it was all-around a good experience. :)
By the way, the audio book I am "listening to/reading" is Fear and Loathing in Las Vegas. Only a few chapters in, but so far it's pretty entertaining!