Thinking of WAN-only sharing, and practical ideas, I don't know why someone hasn't built a baby monitor for the tablets yet. They can already stream audio/video to a specific IP address using the built-in GStreamer framework, I'm amazed someone hasn't thrown a python GUI on that functionality ("Please enter the IP address of the receiving tablet" with the first 3 numbers filled in, because it's a good assumption that you're going to be on the same network, and "Please enter the IP address of the monitoring tablet" on the other one)... Then you just leave the transmitting N800 face down with the camera and mic pointing out into the room, and walk away. If the connection between tablets is broken for a certain period of time, the transmitter keeps trying to re-establish the link, and after 1 minute the receiver starts flashing and beeping that there's something wrong.