I got my TI Bluetooth SensorTag Friday, and played with it some over the weekend. It's pretty nice. It's basically a small device with a bunch of embedded sensors on it - accelerometer, gyroscope, ambient temp, IR temp (see below), humidity, barometric pressure, and a couple of buttons on it. It's very small, and communicates over Bluetooth 4 LE. You can download an iOS app for viewing the data, so my daughters and I played with it some. Pretty cool. There's a teardown of it at MAKE magazine, and even a Raspberry Pi project to interface with it. W00t!!!