In case you have also been taken in by Google's stories about how you can't read Google Books on Kindle, I have great news for you: it's simply not true. For some weird reason, I kept believing Google's claims and never checked it out for myself. Now, I finally decided to look into it and discovered that Google lies like a college administrator. Converting Google Books that come in e-pub format to Kindle's MOBI format is extremely easy and completely free.
All you need to do is download Calibre (for free) from here, install it, and it will convert all your e-pub Google Books to the Kindle format in the matter of minutes. Then, you can either have the program send the converted books to your Kindle by e-mail, or just download them to the Kindle yourself via your USB cord. It's beyond simple, people.
I just downloaded three XIXth century Spanish novels that my library couldn't get for me for love or money. Did I mention how I adore my Kindle?