I was actually looking for something quite different (a small zippered neoprene bag for my iPod earbuds), but I ran across this product ...
http://www.travelgear.us/servlet/the...arge%29/Detail
it looks like it would work really well for just about any of the ebook readers, and note that it says "water proof" not water resistant.
I'm thinking of getting one of these, that is assuming they have a size that more or less fits my Kindle.