Thanks for the suggestion, but that's not exactly what I'm trying to do.
I have a bunch of parts (CM11A's, CM15A's, the routers, etc), and I'm wondering if there is a "cool" project I can do with them.
A PC-independent web interface for X10 (either using the CM11A or the CM15A) would be neat. The router already has most of the hardware needed to create the web host. I still plan to keep the CM15A running off my Windows PC (and I have a web interface for it using X10 Commander), but playing around with another device might be neat.
The other thing is the "status board." for that, the CM11A would be used to "read" the commands coming down the line, and the controller (be it the router, an arduino, or something else) would change the state of the status lights.
I could do the same thing with a whole lot of Universal modules, but that would be an expensive way to go, and I'd have to find a place to plug in 16 (or more) Universal modules, and run the wires to a display panel.
At the same time, an Arduino might be useful for providing INPUTS, as well. Again, PowerFlash modules could provide this function, but they take up a lot of space. It would also be possible (in theory) to program routines into the Arduino to do different things based on combinations of triggers (kind of like using conditional macros in the CM15A).
I know this may sound like "child's play" to some of the more seasoned electronics gurus here, but it is a whole new world for me, and I might have some fun exploring it (when time permits, of course).