How about this question:
Have you had issues with people being reluctant to swipe their credit card into your phone?
If it was some place or someone I knew I wouldn't be apprehensive. The Froyo place we go to all the time just started using some sort of card swiper on an iPad. However if for some reason I was caught between a rock and a hard place at the Chaldean Car Clinic off of 7 miles and John R I may be very nervous(probably for many other reasons too).
Maybe that's just my dad talking though...