Removing a stripped screw or a drywall screw that missed the stud can be a trial — you try to back the screw out with a screwdriver, you almost get it, but it slips back into the hole again. Sometimes you can grab the deviant screw with your fingers or a set of pliers, but Lee Valley sells a tool designed especially for removing stripped screws.
Lee Valley makes the Veritas screw lifter from spring steel, with an arched shape to help you pop out stripped screws. Either slip the lifter’s notched tip under the screw head and press down on the arch to pop out the screw; or push down the arch, slip the screw into the keyhole cutout, and release the arch to pull the screw.
At $9 this might not be a practical tool for everyone, but if you put up a lot of drywall, it could save you some time — especially if you’re not very good at hitting the studs.