I'm digging all the new home automation stuff that's been coming out the past few years. I've slowly been starting my own collection of networked sensors and controls, reverse engineering the various protocols, and adding them to a custom dashboard. It's voice controlled (Chrome has a speech input JS API built-in now that makes building that easy), and responds to voice commands with dialogue from Star Trek LCARS responses (sound clips taken from the show and cleaned up). Lots of fun.
http://i.imgur.com/G4SYEiJ.jpg