I’ve been considering the Ursack system for protecting food from bears.
Those who try Ursack seem to like the product. But it’s not currently approved for use in the Sierras.
I currently use a 2 lb 9oz Bear Vault. It’s great.
details – Amazon
… On the other hand, the Ursack V27 that holds almost as much food weighs only 7.5oz. (Recommended is to use a small Brillo pad squeezed under the opening to protect your yummies from mice and insects.)
Calipidder posted a terrific comparative review of all the available systems.
(via Two-Heel Drive)
besthike.com 
The Ursack is not bear proof…but then neither are canisters. 😉
Having said that, I own two Ursacks and use them 99% of the time when backpacking. I only take a canister if it is required. I bought my first way back in 2002!
They are a great system but must always be used as described – and are not a good choice in areas with highly habituated bears. Most areas in the US they are great though!
Chances are you will LOVE it.
Thanks Sarah.
I think I will buy an Ursack. I’m quite happy with my canister, actually, though it is bulky. The Ursack will be better for the shorter hikes.
I used Ursacks on the West Coast Trail without the aluminum liner and never had a problem, though I never saw evidence that a bear tried to rip them open either.
-Hank
I backpacked in the Sierras and stored food in both a cannister and an ursack. We properly secured our food while we camped. We woke up one morning to find our ursack still secured to a tree, but the entire bottom had been clawed and bitten to shreds and our food was gone. If you would like to keep your breakfast in one piece and free of bear saliva, I would suggest sticking with the cannisters.