Packrat, for those not in the know, is the only full-fledged Backpack desktop client I've ever seen, and it's especially killer because it does offline editing for all your Backpack items and pages. Its developer, Rod Schmidt, just added a key new feature that's been on everyone's request list, including mine: list reordering. This new v0.91 has a simple keyboard shortcut (cmd-r) which presents a sheet with any and all lists on a page, offering drag-and-drop reordering goodness.
Packrat is a Universal Binary and available from infiniteNIL Software for a mere $24.95. A free demo allowing the first 4 pages of your Backpack account is also available.