I like Lance's pattern especially because it makes the pocket from a single piece of material, which saves a lot of piecing and sewing. The only change I'd make is to add maybe 1.5" to the top, to make a fold-over cover for the zipper. That would do two things: protect the pocket from rain (just a bit!) and give a little more support to the ends of the zipper. I might also sew on some velcro hook under the elastic, and hand stitch velcro loop patches on the hip belt to keep the pocket from sliding or rolling under with movement.
Have you seen McHale's large hip belt pockets? The pack end is attache by a bungie, which allows you to pull it out away from the belt to more easily see what's in it. Very clever! Plus it's big enough to hold a Tom Harrison or other map, plus a Suunto.



