Kind of an odd topic here.

I generally use Conti tubes, but the folded tube plus box takes up what seems like a significant amount of space compared to other tubes (specialized) I've seen a some local shops. I'm trying to cut down on what I carry, so I'm looking for the smallest (or close to it) folded tube around. Don't particularly care about weight, just volume. And it doesn't need to be any every day tube...just enough to carry me ~30 miles if I flat far away from home.

Any thoughts?

well, latex is thinner than butyl and will probably take up less space (but i won't use latex, even for racing). i won't worry about it though. open the stem valve & try to squeeze as much air out as possible

I roll my tubes starting furthest from the valve. I open the valve and start rolling up the tube. At the end I make sure that the valve is closed or the tube will sometimes suck in air. If there's a bubble I'll reroll the tube so it's smaller.

The latex/butyl tubes are very thin and will probably roll up even smaller.