I think you need to define "pocket sized" as that means a lot of different things to most people. I assume you want it thinner so it doesn't distort a pocket (even some cargo pockets can't take some thick mess kit style cases). Do some searches for cigarette / cigar cases as well as metal wallets. I've found some pretty interesting cases that way, though they are usually pricey. I've also seen some neat cases in electronics departments amazingly enough. Usually for hand held games or PDAs, etc. worth a shot to look there. Online you can search for metal cases for PDAs, cell phones, iPods, etc. I'm sure they make them in aluminum like my Rino case for my Axim PDA.

Anything taped up with black electrical tape is "water resistant" and not really water proof. Though it should hold it's own if you've carefully applied the tape and the surface was cleaned prior to application. You could make your own gaskets too or use teflon tape or silicone for a more ghetto approach.

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