Philips has a new kit of wireless LED colored bulbs that you can use to remotely control the color of the light bulbs in your house. The basic kit comes with three LED bulbs and a wireless remote bridge that can control up to 50 bulbs.
Phone apps to control the lights are available for iPhones, Android, and Windows Phone. One of the apps, Oni Light Control for Windows Phone lets you create presets and even select colors from photos stored on your phone.
The wireless bridge comes with its own API so that you can create custom applications. The API is accessible through http requests and uses JSON to transfer data.
Channel 9 MSDN has an interesting sample project where you can setup a custom app.