Nan at Life Is Like a Lunchbox has an overview of free audiobooks on the web, including the ESV:
And last but absolutely not least, what would this list be without a reference to the greatest and most influential classic of them all which can be read and listened to in its entirety for free online? At esv.org you can both read and listen to the Bible, from cover to cover, for free. Simply click the chapter you want to read/hear and at the top of the passage click the word listen and it will automatically start playing. This is a wonderful, beautiful gift that ESV has given to us. Naturally, as a Christian I find explicit and unequivocal value in the reading or hearing of the Bible. However, even if you are not a Christian, the Bible has decidedly been one of the most, if not the most influential book in all of history for many reasons, including that it is the story from which much of ancient and modern literature has gleaned many of its plot-lines and therefore should be read by all as literature if nothing else. I remember even having to read portions of it for my Advanced Placement English class at my public high school.
You can listen to the ESV for free; you can also buy an MP3 download of the ESV (read by Max McLean) if you want to hear the Bible even when the Internet isn’t available.
Also, look for a new audio recording of the ESV this fall—online and on CD.