kerry wrote an answer about Bear Vault BV500 Bear Resistant Food Canister on August 17, 2012
Based on my last trek in Yosemite's bear country, I would not bother hanging the canister. Our 3 canisters and camp kitchen items were sitting on a rock in the open quite a distance from our camp and were not disturbed by bears. A group near us, however, weren't so lucky. What were the bears after? The nearby group put their camp kitchen items (stove, clean pots) in a bag which for some reason they hung. The only thing the bear went after was the hanging bag. Bottom line, at least in bear-rich Yosemite where they have experience with hanging food bags - bears see a hanging bag like a neon "EATS" sign so why hang something that will no doubt be an attractant? In my opinion, you're better off securing the food in a canister and placing it a good distance from your camp in a manner where it won't roll away if disturbed by a bear. If the bear wants it, he/she will get it, but will hopefully lose interest after not being able to open it.