Embodiments of {TAIL ~ the disclosed technology} comprise {HEAD ~ a handheld display device} with built in accelerometer and, in some embodiments, compass 
Embodiments of { TAIL ~ the disclosed technology } comprise { HEAD ~ a handheld display device } with built in accelerometer and , in some embodiments , compass
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH