Or maybe just use a Nintendo Wii remote and the GlovePIE API like done here... http://nintendo-scene.com/382
How about creating a plugin to replicate something like the GTech (http://www.gtechpro.com/) in CF? Phidgets sells a USB-based accelerometer (http://www.phidgets.com/products.php?product_id=1053) and provides an API that could be used.
I would pay for this plugin!!