I have a small frame an extremely short torso, and thus have had a terrible time finding a pack that I can climb in comfortably. I have finally found one, and thought I should share. The Patagonia Gritty pack (way expensive, but perpetually in the web sale part of their website) is perfect for day trips on rock and ice. It's easy to attach tools and crampons to the outside of the pack. The "regular" size is just big enough for a day's worth of gear if you take out all the foam and weird aluminum stays. It's narrow, so you have a good range of arm movement, and short enough that the waistbelt can sit above my harness and I can still tilt my head back to look at where I'm going even with a helmet on. For the approach, I just lengthen the shoulder straps to let the pack rest on my hips. The pack is bigger then anyway 'cause it's full of climbing gear. And it's not unreasonably heavy. It's not a pack for the tall and wide, but if you're small, it's great.