Today's smartphones can do a lot of things, but none of them have a sensor that lets them measure stuff. This sniffer called the Sensordrone fixes that, letting your phone measure everything from gas levels to temperature.
What's really impressive is just how many different types of things the Sensordrone can detect and measure. Everything from airborne gasses, temperature, pressure, humidity and light intensity can be measured. This lets you use a smartphone coupled to the Sensordrone as a carbon monoxide meter, blood alcohol level tester, thermometer, weather forecaster, altimeter and a bunch of other things limited only be what apps are developed. The Sensordrone smartphone interface is open source, so anyone can develop new apps for the platform.
Sensordrone is a Kickstarter project that has already doubled its fundraising goal, so it seems likely that this will get built. But I keep thinking how much less clunky it would be if you simply built the sensors into the phone in the first place.