For the final project of one of my classes, I modified Beats so it would take input from an XBOX Kinect. The result is a Kinect hooked up to a Beagleboard-xM running Android and playing Beats. It was all proof-of-concept of course as everything ran with extreme lag, but it was pretty cool nevertheless and fun! Here's a pic of my lab partner mastering Tetris (Rock Version) on Beginner[1]:

More pictures are posted posted on the Beats facebook page here
For more info, see the (currently still being updated) blog here. The modified, signed APK can be downloaded here. The patch file (for inspection-purposes only) can be found here. The modified ofsample demo used for calibration can be downloaded here. The (possible?) source for the demo can be found here. Make sure to recompile your Beagleboard's Android kernel with 'CONFIG_USB_DEVICEFS=y' and add 'mount usbfs none /proc/bus/usb -o devmode=0666' to your init.rc file as per instructions found here.
Happy hacking!
~Keripo