I often use my laptop to run a projector and write on a chalkboard intermittently. This used to create huge moraines of multicolored chalk dust in the keyboard of my last laptop. There was just enough finger-oil mixed with the chalk dust to cement it and prevent vacuum-cleaning. Also, I would like the skin to keep out any spills, or keep the computer safe while cleaning with rubbing alcohol. I personally prefer to use things with dirty hands and then clean them, I find it much easier than keeping things clean or living with dirt. So, where do I buy one? All the websites I have found are selling them for old MacBook Pros, and I have the unibody version.