I just took a look, it has been a few years since I worked with the thin clients and I just don't see any good options in that area right now (prices too high). The idea is a small computer with a flash based hard-drive. They are low power and no noise. If you see such an option, take a close look.
As for "off the shelf" - x10 is an example. Any automation products you an find that allow for microprocessor control and/or has a web interface will be a good candidate for easy integration.
Details on my home grown thin client / off the shelf solution:
- HP Zone control using (off the shelf) XP Embedded based thin clients
- IR control using (off the shelf) - http://www.usbuirt.com/
- Music control via media player control running in XP thin client app
- X10 control using RS232 controller (off the shelf)
- Example: http://store.homeseer.com/store/TI103---X10-Computer-RS232-Interface-ACT-HomePro-P20C45.aspx
I was working with x10, but not the wireless transmitters. Instead I would use the computer based x10 control via a serial port. This was then run on a thin client with a web interface to create a quiet/low power zone controller. The zone controller also provided IR input and output as well as picture frame and music for the zone - all custom apps using raw RS232 comm control. The thin clients even supported ELO touch screens, so the picture frame could also double as a "house and zone" menu system. Even with no touch screen the IR would allow a standard IR remote to control the on screen menus (i.e. via the TVs VGA port for living room).
It is easy to send web commands to other zone machines from any other machine. Why a web interface, if possible, is almost a no brainer.
If I were to expand this system now, I would create my own web enabled shade / curtain controllers and a web enabled sensor panel via arduino.
Most of the thin client work was created using VB6 and running on embedded XP. Apps could be run from a flash drive directly or via the LAN.
This was long ago, much cooler stuff is bound to be out now - just giving some perspective on using some off the shelf products.