I live in California and backpack a lot and a few years ago Yosemite park made it mandatory for all backcountry travelers to use a bear canister(avalaible at REI and similar stores).There are 2 types,one is plastic and another is aluminum and both resemble a small beer keg.I read a magazing article where a guy had a grizzly bear that he used to test such gadgets and they did their job well but the bear was eventualy able to pop open the l lid on the plastic one.Now this was a semi tame huge 1000lb  grizzly that is an expert at breaking open"new designs" and it took all his strength  and a lot of time to open it.So for black bears it would be great.The only drawback is that they arent very big and for storing eggs and meat and large items it wouldnt be very good but for freeze dried foods and smaller items it would be perfect and you just leave it out.It is to clumsy for a bear to carry and after he fools around with it for a bit they get tired of it and move on.