The most used piece of kit in my kitchen is my saucepan. I use it every morning to cook my porridge in. The least used piece of equipment? I'd say a food mixer. I've never used it I don't really know what they're for.
To me there is something superbly symbolic in the fact that an astronaut sent up as assistant to a series of computers found that he worked more accurately and more intelligently than they. Inside the capsule man is still in charge.