I've taken my Sony 505 to the beach the last 2 summers and I love it. I bought an M-edge cover that zips up and has a clear front. My beach chair has a pocket so I just put it there when not using. I used to haul several boxes of books to the beach for a 2 week vacation and it is SO much nicer to just bring my reader loaded with books. Here is a link to a waterproof kindle case from Amazon or you could just go with the ziploc bag.
http://www.amazon.com/Version-Trendy...2121228&sr=1-1