X11 Serial Killer?

Chris Benard asks: "I frequently have problems with X just taking control of my keyboard, but not my mouse. My mouse still moves, but it isn't able to interact with X (not unlike a windows freeze). However, I would like to know if there is a program to listen on a serial port for commands and execute them as root. I have an HP48G calculator, and I would like to make a few short commands to execute from it to my serial port, such as killall -9 X and killall -9 netscape-communicator. Please let me know of any programs existing and any SDKs that I might use to produce my own program. " Has anyone managed to come up with a hack that might work for this situation?