I keep being intrigued by Philips' smart lighting system. Philips released an official API with iOS SDK in March, and today's update brings great new features such as geofencing, which you can use to automatically activate your hue lights as you walk in or out of your house.
In terms of automation, hue is now officially integrated with IFTTT, which should allow for some interesting "workflows". Examples mentioned by Philips include changing the color of your lights based on Instagram pictures, the weather, or your favorite sports team. I can't wait to get a hue set and start playing around with IFTTT triggers.
You can read more on hue/IFTTT integration here.