[TomDavey]

Invoking the help system by typing C-h b (the command "describe-bindings") will open a new buffer showing all the keybindings in effect in the current buffer. Picking an unused binding to your liking is a matter of scanning the list.

The Emacs help system is a marvel and an astonishment. It's the second thing to explore after running the built-in tutorial. And it's the first thing to master.

Don't neglect the hyperlinked, highly navigable Info Manuals, which you read right within Emacs. They are among the most literate technical documentation I've ever read.

[asgard1024]

Yes, I am aware of all that. Still, there can be various modes in effect, so it would be nice to have a function that would do a pick (that would work in all modes) instead of me scanning the list all the times.

Also, it would be nice if I could easily remap all keys with the given prefix. Maybe someone wrote library for these things already, I don't know.