Carburetors, hose clamps, prying apart electronic connectors, electrical outlets, mixing up a batch of JB quick.. Tons of uses im forgetting about here! The flat head screwdriver in itself is a valuable tool. Good quality flatheads can serve as a small prybar, but im getting away from that as I bought a small prybar that is perfect for those situations. Find yourself in a situation where a phillips has rounded out? With a Dremel, cut a slot in the fastener, and remove it with a flathead. I have no love for flathead fasteners, but good flathead screwdrivers are a toolbox staple.