Deadly Computer Blog

These nifty picture frames, designed by Matty Salin, have motion detectors and are networked together.  When someone passes in front of one frame, its counterpart lights up.
When no one is moving in front of the other frame:

When the frame is activated by someone looking at its counterpart:

There’s a few other interesting contraptions on his site too, like the pulse lamp, which pulses with light in time with your heartbeat, and the wake n’ bacon, an alarm clock that wakes you up by cooking a piece of bacon instead of with an annoying buzzer.