Actually, after following Aprilbeginning's Quick Cover topic I have been playing around with a design for a light rigid slipcover for a friend. Not as protective as M-Edge's but for those of us just dropping it in a briefcase or leave it sitting around it could offer an extra couple seconds of protection.
Hmmm, if I make a product (even if it doesn't sell) can I write off my Sony as a business expense? (Maybe I could convince the IRS that all those ebooks I bought were for testing to see how much the added weight would affect the cover fit of the final product.) Hmmmmmm......