The trouble with pots is they won't be there when you don't bring your full gear.
I approach it from another direction- how far can you strip your gear and NOT have a pot or reasonable facsimile to boil water in. I do not mean folded up and soon to be leaking aluminum foil anything. (snip...)
The only reason to NOT have a pot or cup or a metal water bottle (I find the Goyet's superior in fit and function to the Kleen Kanteen, IMHO) is if circumstances leave you with only what was in a secured pocket or dog leashed to your person. (snip... )
But if what you are thinking is more heavy duty altoids-sized tin, why bother? It isn't enough water to stress on honestly. I'd rather have chlorine tabs and a turkey roasting bag than to boil water less than a quarter cup at a time.
Lots of very good points. If I have my pack I have a pot, simple as that. I'm looking for something small enough to be included in a pocket survival kit, yet big enough to be of practical use. Those altoids tin seems awful small for the job...
The "Arctic GI cup" shown above looks perfect for inclusion in a bag kit, but still a tad big for pocket carry. So is the cups around 2 inch diameter: Perfect for most bags, slightly uncomfortable in the pocket.
I think the best bet so far would be to cut the top of a 10 oz (2.3dl) or bigger oval or kidney shaped hip flask. Cut off the top, add two holes for suspension and of course you stuff it with PSK items. Small enough to be comfortable in your pocket, big enough to be useful (just below your quart pint limit) and with a shape that goes well with suspension from a string or wire. I'll do an asymmetric cut so the opening is slightly lower on one side, this makes filling with snow easier.
Anyone who knows about where to get stainless steel hip flasks bigger than 10 oz?