What's cooler than an Apple ( MacBook)? A MacBook only you can see. And the maker of the Post-It, 3M ( MMM), makes just such a wonder device. This heavily polarized, stick-on plastic screen guard not only protects your beloved Mac but ensures that only the person sitting right in front of the computer -- that is, you -- can see what's on it. And if you don't think that will turbo-charge the proprietary work you do on your next flight, think again. Trust me, giving this kind of privacy to customers is worth $32.50.