Arduino Infrared thermometer
educ8s.tv has posted another great video tutorial on building an Arduino infrared thermometer using the MLX90614 Infrared temperature sensor, which uses the standard I2C protocol to communicate with the Arduino. The measured temperature is displayed on a Nokia 5110 LCD display shield. The device can measure the temperature of an object without any physical contact and with just facing the sensor toward it from a small distance. It can measure temperatures from -70 degrees Celsius to 380 degrees with an of about 0.5 degree at room temperature.
DIY Arduino infrared thermometer
Demo video showing it in action.