Wish I had followed this thread back in November. This is one of my concerns. I have the GSI cup that fits over a Nalgene. I have made an entire kit around it and carry it in my briefcase daily as well as slipping it in my pack when I'm outof doors.
I'd love a container that I could use to hold a pocket kit that would also double as a cook pot. Problem with Altoid type tins (aside from size) is that they are oriented the wrong way.
30 years ago, as a kid in Scouts, someone was giving us a wilderness survival class and I remember him pulling a metal band-aid box out of his "survival pouch" and saying he kept it in there to use as a pot to boil water. I've always thought that something like that would be about the correct size (maybe a little big) for a pocket kit. But the Band-aid boxes had seams, were made out of tin, and are largely unavailable now.
I'd really like to see a "band-aid" type box made out of stainless steel (or titanium) similar to my GSI mug (i.e., no seams and similar handles - a snug fitting lid is also part of my wish). Such a kit would fit in a cargo pocket for outdoor pursuits but would not necessarily be my EDC pocket kit. I am constantly looking for such a beast but to no avail.