I found the Ziploc® Big Bags at my Safeway!!! These are giganteous. It's not the piddly 1 gallon, or even the more generous 2.5 gallon...it's like so big they don't use gallons to measure. It's so utterly fablous, so voluminous, so good for storing yarn.
The funny thing is that the Ziploc website lists what these bags are good for storing:
Linens and pillows
Books and photo albums
Umm, aren't they forgetting something?? I want to write to them and say they should advertise in IK!! I was so excited because prior to finding them at Safeway, I thought I would have to order these from some industrial company and then in some huge quantity like 100 crates.