over here we have small things called bumpons which are as you describe, little rubber dots in several different sizes and shapes that can be stuck on to anything you need to mark, from a computer keyboard to washing machine or microwave controls.
those are really good for staying on. In 2009 I used one to mark the C key of my laptop because I was extremely unwell and lying down while I used it to listen to audiobooks with winamp. Since I didnt' want to getup and find the home keys everytime I wanted to use Winamp's controls, marking c was an easy way around. that bumpon was still on there last time I checked that laptop, albeit it's been stuck in a cuboard for the past few years since first the headphone socket went, then of course it's an xp machine that is not really usable, still it says something for bumpons.
Ditto with washing machines, buttons on microwaves etc.
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)