A utility knife is like duct tape: You never know when you're going to need it, but you're always glad it's in your toolbox just in case. Irwin has introduced utility knives with BladeLock Technology that helps keep the blade from accidentally coming out of the handle during use. You can change blades only when the release button is engaged and the blade holder is at 45 degrees. Each folding utility knife has a liner lock and a 16-degree cutting angle. The FK100 is lightweight and compact; the FK150 can hold up to two blades; and the FK250 includes a foldout screwdriver for 1-inch insert bits, plus blade and insert bit storage. Price: $11-$16