Oh I love Project G. Its one of my most oft-used bookmarks.
Librivox, on the other hand, I have never heard of. As much as I love audiobooks, I tend to be really picky about the voice (and, frankly, acting ability) of the person reading it. I see them more like performances than books.
That said, I'm looking forward to checking it out. You never know when or where the next great book of your life will come around.