Measuring the absolute pressure of the enviroment using a digital barometer like this has some interesting applications. By converting the pressure measured into altitude, you have a reliable sensor for determining the height of your robot, plane or projectile.
Using a sensor as capable as the BMP180 you can achieve accurary of 1m, with noise of only 17cm in ultra high resolution noise. The device will operate at only 0.3uA meaning low current draw for battery powered applications.
The BMP180 comes fully calibrated and ready to use. As the device operates over I2C we've added optional I2C pull ups that can be enabled using the PU (pull up) jumper on the board for your convenience and ease during breadboarding.
Using I2C, the device provides pressure and temperature as 16bit values, which are used along with calibration data within the device are used to provide a temperature compensated altitude calculation.

Specification:
Type: Barometric Pressure Sensor Module
Model: GY-68 BMP180
Features: BMP180 Replace BMP085, Digital Barometric Pressure Sensor Module For Arduino

Package Includes:
1 x BMP180 Replace BMP085 Digital Barometric Pressure Sensor Module For Arduino