The Unseen Video
This is unbelievably cool: The Unseen Video.

The video is partially dynamic; based on your IP address, it gathers data from your nearest weather station and the video unfolds accordingly, the look of the piece taking its feel from the weather outside your window.

Since it is dynamic, the video is never quite the same twice, and they even have a Flikr gallery of screenshots that people have uploaded.

Warning: a certain amount of processing power is needed.