If you don't want to wear a backpack, try CamelBak's Montara 45 oz Lumbar Pack. It's perfect for when you need water at your disposal but don't want to carry it on your back. Just fill up the water reservoir, stick your keys in the two zippered pockets, stash your energy bars in the two stretch mesh waist-belt pockets and off you go for a perfect day. CamelBak's has a strap management system that secures the ends of your straps so they won't flip up and down with each step you take. Volume: 150cu in (2.5L).