I always read out my dialogue. Always. Which is annoying when I can't do the accents my characters have in their heads, but I think it does wonders for the realism.
I love audiobooks. I don't drive, I'm a dedicated pedestrian, and when I walk somewhere I often listen to audiobooks on my iPod. I get a lot of books from Audible. I've listened to all the Harry Potter books as read by Stephen Fry, working my way through The Dresden Files read by James Marsters (who has one of the sexiest voices on the planet and has an uncanny ability to make the most gruesome descriptions of death and destruction sound sensual), A Song of Ice and Fire read by Roy Dotrice, Neil Gaiman's Anansi Boys read by Lenny Henry, American Gods read by that guy whose last name I can't spell, the same in full cast recording, and I could go on, but those are my favourites.