I've looked at X10 and passed on it before. The Insteon seems more durable, a friend uses it. It's wall mountable as well, versus plug in only.
The biggest plus is that I can control it from my iPhone or Touch. My plan would be to get it to run on Mac Mini/iMac and then use the iPhone/Touch as the portable controller. Then when I'm out of the house or on travel, I could VNC into my Mac for remote control. I already have a webcam that I can see from any browser and it's cool to check on the house when I'm not there.
