Dot-difference-to-X converters. If we get to making actual interactive technology such as a calculator with working buttons, this might help.
Here's one when I brought the conversation up a few months back
Extrementhusiast wrote:
muzik wrote:If you can do this, and also extract some sort of glider output from it, then this could possibly be used as a "button" for something like a functional calculator, if anyone ever gets around to building such a crazy project.
A few years ago, 'Guam' had made a one-bit-spark-to-two-gliders converter: