I've always used ammo boxes, but the problem is that they are so heavy!!
I was going to use those cases that some moving and storage companies lend you, but they are really quite big, and by the time you fill them with stuff, would be a pig to move.
These (goto the "food grade storage" section);
Plastor containers and handling
Look like a good alternative, not as strong as the wolf boxes, but a fraction of the price. They stack and have a far larger size range. When I get round to figuring out what I do and don't need, I'll be getting a few for my camping gear.