This is a device a built a few years ago to measure and record acceleration in 3D. It records acceleration from three perpendicular MEMS accelerometers at 28.125 samples per second (that rate was convenient, trust me) and stores it in serial flash.

The microcontroller is at AT90S2313 (now obsolete) running at 3.6864MHz. The sensors are Analog Devices ADXL210 dual-axis MEMS accelerometers, which can measure +/- 10g.

It's built into a Maxim free samples box. There is a watchband attached to the device so it can be worn on roller coasters. The four-pin header is a serial port for downloading data. It can also stream data in real time - this is used for calibration.