This may be better than a watchdog. The Motion Tracking Camera automatically captures movement by panning 180° and tilting 60°. Control the camera remotely with software via the Internet and set it up to automatically email you when it knows someone is in the room. The cam captures 640x480 res video at 30 fps and has a 4x zoom and built-in microphone that can record up to 20 ft. away from the subject. Compatible with Windows XP/Vista, you need a high-speed connection. The 4 1/4 x 3-inch webcam plugs into your USB 2.0 and carries a price of $89.95.