gila: I think tattooing is a worldly trend. Christians should stay away from such trends. I try to keep things simple....
Using computers is also a "worldly trend" - but you clearly don't avoid using computers just because of this. Computers aren't very "simple" either. So you haven't yet given any real reason for Christians to stay away from such "trends" as tattooing.
Luk 14:27 And whosoever doth not bear his cross, and come after me, cannot be my disciple.