It isn't the first time it's been done apparently, but it's the first time I've seen it. Chevy Truck's ad agency worked with a company called Americhip to put a video player inside the page of my magazine. It powers on when the plastic tab you see at the left side in the fold pulls out and allows the battery to complete the circuit. You select which video file to play with one of three buttons on the right hand side. On the back of the page is a perforation that reveals a micro-USB connector. I tried plugging it into my computer but it didn't show up as a drive, so it appears to only serve as a charging port with video files hard set in the memory chip.
I'll play around with maybe tearing it down and seeing if the parts are hackable over the weekend.