This is my baby monitor setup. It uses a GoPro (already owned) and a BeagleBoard. If you have a webcam lying around this is a lot cheaper than any baby monitor out there. If you have a webcam and a raspberry pi or something lying around, it's free.
Point-to-point encrypted video from a sender with a GoPro plugged in with a USB cable to a receiver at 192.168.0.2:
Point-to-point encrypted video from a sender with a GoPro plugged in with a USB cable to a receiver at 192.168.0.2:
Sender:
Receiver: