In case you just want to remove the paint from the caps you can use a good chemical solvent to rid them of most of the keyboards available today (except the ones with laser etched keycaps).
Even cheaper (and reversible) solution is to remove all square keyboard caps, put them into a bag, stirr well. Then assemble them top-left to bottom right while drawing from the bag, scrabble style. This fucks up a keyboard reliably enough to drive away average users within seconds, so you have your machine for yourself.
While the optimus keyboard sounds nice in theory i don't see a point unless you're really switching constantly between several esoteric keyboard layouts.