So, after having taken the N800 some more places with me in the case Nokia provided, I have found the case to be far too slippery, with the N800 sliding out too easily and almost crashing to the floor a few times. Even inside a (day/back)pack, the unit slides out offering too much opportunity for the screen to get scratched.

As has been pointed out by others, the unit is priced such that I should not have to customize the case or unit to have a pleasant user experience. In this instance however, I am thinking of adding some kind of velcro strip across the opening to keep the N800 from going out of warranty prematurely.