An extra hand sure would help when you're working alone in an awkward position -- up a ladder, say, or down on your hands and knees. But here's a fast, practical solution that some experts use: Keep a tube of woodworker's superglue, sold in woodworking shops and hardware stores, handy in your pocket or tool belt. When you need to nail or screw two pieces of wood together and can't hold both pieces at the same time, dab a little of the superglue between them, hold them in place until the glue dries (a matter of seconds), and then drive your nail in. Make sure you use fast-setting superglue, whose main ingredient is cyanoarylate. This trick can also work for plastic, metal, and other materials. It's the best solution -- hands down.