An incredibly useful module would be a small panel with LED lights that indicate the state of AHP Flags and/or the state of various X10 address modules. For instance, so you could see if you the flag or phantom module for a particular function was set (vacation timing on/ off, wake up light sequence on/off, etc). One could make something like this using nightlights and a LOT of appliance or lamp modules, but that's expensive, and would take up a lot of space, and look really goofy.
Perhaps a row of LEDs to show flag status, and another set of LEDs to show the monitored house code in AHP.
Would be even better if they didn't have to be all on the same house code, but I'd settle for the above.
A much fancier (and I'm sure expensive) device would be an LCD panel of some sort that AHP could write messages to.
Another possibility would be a way to have a laptop on a home network communicate with AHP to find out the status of modules and flags. I'm not talking about logging in remotely or with My House, but simply a way to "poll" module status or flag status from a computer that is not necessarily the one running AHP or connected to the CM15a. (The above suggestions for stand alone readouts would probably be better, but this might be nice, too).