This is by no means my idea, and most likely it appears elsewhere on here, but when I get my reader I'm planning on making my own case...out of an old book.
You can find tutorials on how to make secret hiding spots inside books (youtube videos, etc). I'll just make my 'hiding place' big enough to hold my reader. I'll most likely line it with some sort of softer material to absorb shock and movement, and attach some sort of string/peg on the cover in order to tie it or wrap it shut.
Positives:
Doesn't look like a carrying case for an expensive electronic device, so it scares away thieves.
Cheap. Although I'll have to wreck a book to do it. I'll just pick a book I don't like.
Customizeable.
Negatives:
Will take time to make.
Might be heavier than an average case.
Not sure if I'll be able to fit accessories in it.
I found a link to the process of making a case that would work for this:
http://how2dostuff.blogspot.com/2006...llow-book.html