2 things...
1. can't help but wonder if the phone will be able to take the shock from a rifle repeatedly
2. picture this... you're about to shoot a perfect score... you focus on the target, you breath in, then release.. slowly squeeze on the trig.... RINNGGG RRINNNGGGG RINNNNGGGGG!!!!! fkjdsak;lfdjlsk;afjslka;fj/.... perfect score ruined! STUPID TELEMARKETER CALLING
But beside those two things, conceptually it is VERY COOL!... also you can play angry birds while standing around