I just saw this on eBay. I'm not sure if these have been offered before, but I think it's an awesome idea.
http://www.ebay.com/itm/Mounting-Bracket-for-X10-Eagle-Eye-or-Active-Eye-Motion-Sensors-/261709103554?pt=Home_Automation_Modules&hash=item3cef1401c2
Looks to me like someone has a 3d printer and an interesting idea of how to use it. I don't know whether it's worth it for this guy to continue selling these based on the cost of supplies, so if anyone is interested, I'd jump before they are gone.
Nice find.
I am sure it maybe a welcomed part to mount an X10 motion sensor.