Hands, neck and face are still taboo, so I wouldn't recommend getting them unless you're already 100% 'proven' guy(the jobs hunt you, not the inverse)
I think all the rest, including lower arm are OK in IT generally as long as you care about your posture and presentation(don't forget to be good at what you do, of course)
I got my first visibly-visible one(on my pulse) 5-6 months in and nobody cared, I didn't ask for permission or mentioned it... I think it would be like going to the boss and asking if I should get my hair cut or not
I think all the rest, including lower arm are OK in IT generally as long as you care about your posture and presentation(don't forget to be good at what you do, of course)
I got my first visibly-visible one(on my pulse) 5-6 months in and nobody cared, I didn't ask for permission or mentioned it... I think it would be like going to the boss and asking if I should get my hair cut or not