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