Wiebetech is selling an amazing new USB device. It's called the Mouse Jiggler, and it costs $30. If you can't tell from the name, it's a USB dongle that makes your mouse jiggle. That way the screen saver doesn't kick in. It is very stupid. They come in fast and slow jiggling versions. I know what you're thinking, "What about someone like me that desires medium jiggle?" Well my friends, you're out of luck.
Product Page [thanks to Derek for the tip]