Control X10 devices from XBMC
XBMC is the most popular and the best option for DIY media center I think. But it doesn’t cover any smarthome areas except entertainment. Luckily XBMC provides plug-ins and scripts which allow en easy way to extend basic XBMC functionality. So, to add possibility to control X10 devices to your media center you may use either heyu + some scripts or plug-in X10 Commander Lights. Which one to use is up to you. The first way is more difficult but it’ll give you a full control and understanding the low-level logic while plug-in provides easy way way. Even for non-geeks. It’s always good when you have more then one way to do something.
I’d love to see more of this with future versions of XBMC, we are starting to see KNX and other home/automation and lighting control system add-ons. There are a number of very powerful iPad based XBMC control systems on the horizon, it will be interesting to see how good they are.