I've been really enjoying my NEST Smart Thermostat, and now they're unveiled another project that I'm excited to get. Called the NEST Protect, it's a Smart Smoke Alarm and CO2 Detector. It's designed to produce fewer false alarms and less annoying alerts.
Just like the Smart Thermostat, it connects to your home's wireless network and has a corresponding app for your Smart Phone. When the NEST Protect notices an increase in the amount fo smoke or CO2, it gives you a vocal "Heads Up, there's smoke in the [room]". If the problem isn't a big deal you can wave your hand in front of the Protect to stop the alerts (until the problem gets worse then it will re activate).
Available for $129, you can order it from the NEST website, Amazon, Best Buy, Home Depot and the Apple Store. I'll definitely be adding this one to my collection.