Evike.com Multi-Purpose Tactical Self-Seal Ziplock Bag (Color: Black)

"Solid bag does the job although it's not that good at holding milk.

"These bags are so cheap, you might as well throw one or two in any of your orders like I did. it's just your standard plastic ziplock bag, except a bit thicker and with the evike logo. It can be rolled up and such, and like the description says, it can stand on its own when its filled with something like BBs. Since it's waterproof and such, a good use would be for a piece of your gear that fell off or something. Toss it in the bag, roll it up, pack it away, take it out later.

There's really no cons, it's 60 cents, durable, waterproof, so on... buy one.