Having been away for a couple of weeks, I return to work to find that the normal computer keyboards had been replaced by 'dirt free' keyboards that flash at you when they need cleaning.
Nice idea, but very open to abuse.
All you need to do is switch it off and rub your hand across it and it stops flashing at you.
Pressure sensors are all well and good, but gently massaging your keyboard isn't going to stop it from harbouring skanky stuff.
Take a look here; its actually surprisingly nice to use...