We're working on developing an electronic personal trainer. When we started, we couldn't find an easy to use, plug and play system that could collect all the data and give us the measurements we needed... so we built one ourselves. It's comprised of three 3-axis MEMS sensors to provide 9 channels of data, an onboard microcontroller, rechargeable battery system, and bluetooth module to make a complete 3D tracking system. Is anyone else out there working on motion projects that could use something like this?