Sorry to disagree with you Steve.

Here is a exerpt from the introduction page of the ADXL202 from Analog Devices.

The ADXL202 is a low-cost, low-power, complete 2-axis accelerometer with a measurement range of ±2 g. The ADXL202 can measure both dynamic acceleration (e.g., vibration) and static acceleration (e.g., gravity).


But you are right somehow, the sensor is insensitive on it's 3d axis.