"I have read of people reading in bed, falling asleep and finding the reader on the floor. Do you want to do that with a naked K3?"
arr.. im a bit late to this thread, just been reading through

I am with abookreaderon this one, not rich.. far from it but heh, early on I figured to use kindle like I want to just resigned myself to having to replace it if worst happens. I am an insomniac and reading helps me to sleep (plus meds

) so my caseless / naked kindle has been in bed every single night for 8 months. It has fallen out of me bed a few times.. actually have a pillow on floor beside bed now just incase, lol. That being said, they are pretty rugged wee machines, although it kinda depends on what kind of surface you drop it on. For example say ceramic tiled floor = bad, buy a heavy duty case; wooden floor = best not to drop it; nice carpeted floor with rubber underlay.. meh
The only solution I could think of to make my kindle sleep proof was custom design something outa gorilla glass

, at the end of the day though I figured I would just leave it as is, still looks like a new kindle strangely

. The only problem I have had was I somehow managed to half dismantle it in my sleep one night, lol.. luckily the case pops back together again good as new

as for a case that would protect kindle in backpack from everything.. personally thinking on just 2 plates of steel with some form of rubber shockproof foam / rubber material for the inside

would prolly still be cheaper than most brands.. and actually protect kindle :P