Using a Nokia Lumia or one of the other windows phones you can now control your lights and other appliances (UK only I think).
The system is using LightwaveRF – no PC required!
Step 1: Buy one of these LightwaveRF Wifi things and plug it into your Wifi router
Step 2: Swap your existing light switch for one of these (variety of colours available):
Step 3: Get the unofficial Home Remote RF app from the market place
I thought pairing the devices was pretty easy (much easier than X10 if you’ve used that and more reliable). LightwaveRF also has the advantage of remembering dim levels.
Read an in-depth review at: http://www.automatedhome.co.uk/Reviews/LightwaveRF-Home-Automation-System-In-Depth-Review.html
Although the app featured in the review is for the official iPhone app not the unofficial WP7 one.