This somewhat overlaps with the looong thread "... and a pot". http://forums.equipped.org/ubbthreads.php?ubb=showflat&Number=188249&page=1. Lots of interesting angles to this problem.

The holy grail of PSK container and cooking pot is yet to be found - all those compromises between capacity, ease of use, shape and bulk. Thseng found a source for square, flat containers, no welding seams (page 13 of the "...and a cup" thread) which probably would be a winner - but hit a dead end due to minimum production requirements. If someone has confidence in their ability to sell more than 60.000 of these then that project may come to life...