Ask HN: What do you do when you're waiting for something to run?

I find that when I need to wait for something to run (a compilation, a jupyter notebook cell, a script, etc) is when I'm most prone to embark on something distracting.

The common train-of-thought is "I'm just gonna check _____ for a second while this runs." And then it's never just a second.

What do you do?