* Tools for hittings things to make them loose or to tighten them up or jar their many complex, sophisticated electrical parts in such a manner that they function perfectly. (These are your hammers, maces, bludgeons, and truncheons.)
* Tools that, if dropped properly, can penetrate your foot. (Awls)
* Tools that nobody should ever use because the potential danger is far greater than the value of any project that could possibly result. (Power saws, power drills, power staplers, any kind of tool that uses any kind of power more advanced than flashlight batteries.) -- Dave Barry, "The Taming of the Screw"