This is amazing. My only thought was a double sided sheet of tape that would have the layout of one specific keyboard, ex the macbook bro. It would fit in between the keys so that your fingers wouldn't touch it, but any crumbs would easily stick to it instead of ruining our keyboard. This would have to be sold to the manufacturer so they could make a new design for ever new keyboard layout they make. Not really an ideal thing to make. I could really use that foam stuff though.