I'm a big fan of Balabolka, especially when you get some really decent SAPI 5 voices.
Generally speaking, you want to make sure you break up the audio so it's not always a straight transfer process.
Also, I might add that "Reading Out Loud" is built into Adobe Reader but the voice isn't as nice.
I'll rip whole books using Balabolka and have it set up to create new MP3's for each Chapter. I'm able to listen to whole books in my commuting time in a few days to a week depending on the length of the book. It takes some training to follow the books but you can listen to them really fast after a while.
One other thing is that I often cut out footnotes because they're impossible to follow on audio.
