With flair, the entire circuit and 3xAA battery power supply may
even be able to be housed inside the keyboard - suiting perhaps a serial "computerless" keyboard able to send data for many kilometres along a simple two-wire link (refer "Damp String" Datacomms, July 2003 SILICON CHIP).
In spite of its recent multimedia and Internet variations, the
PC's humble QWERTY keyboard surely is the industry's bargain workhorse, with a service life extending often well beyond its companion PC.
It is debatable in a commercial sense if it's worth cleaning
spills and dirty finger marks off them, since in spite of their electronic and mechanical sophistication, new (barebones) keyboards sell for under twenty dollars - often well under.
But if you're prepared to spend a few minutes wash & brush
up time, you'll no doubt be able to lay your hands on plenty of working ones (maybe even more after office Christmas parties!).