It's pretty amazing that everything we can do with a computer can all be done with the equations of the main Boolean operators AND, OR, NOT, and NAND, determined by two simple switches! The history leading up to modern transistors is really amazing (so is the history of modern storage mediums for that matter). There was heaps of alternative methods that were developed and experimented with, but abandon for mainstream adoption for one reason or another.
Here is a great example I came across recently...