I use these small and medium size tabco business-form boxes. They each hold between 5 and 10 pedals/boxes depending on the brand of course.
They have the nice flaps that tuck-in the front so they stay tightly closed on their own, and even with loaded pedal boxes they're only like 5-10 pounds each.
Not only are they good for pedals, but also for strings, straps, pickups, mics, ect..
Very nice sturdy boxes you can easily grab with one hand, even when loaded, and when you're loaded too that's a good thing.