The ADXL335 is a triple axis accelerometer with extremely low noise and power consumption - only 320uA!
Here's another SparkFun breakout board, this time featuring the Analog Device ADXL335. This one is particularly sweet in that is has very low nose, and current consumption of only 320µA (that's 1/3 of 1 milliampere!).
Note: The silkscreen indicators for the axises are incorrect. Please refer to the datasheet for the correct orientation.