I would love to tell you that we live in a nonjudgmental world, but it's simply not the case. Some managers may be able to look past what you wear- but others won't.
A friend of mine was excited by the prospect of a job in an art gallery. She went to apply on a hot and humid day, wearing a short skirt, a cute tank top, and a pair of slides. Although she was an art history major with solid credentials, she was dressed as if she was going to the beach rather than to a job interview. She didn't get the job.
The real reason for dressing up a notch is that you want the interviewer to focus on you, not your clothes. If the interviewer’s attention turns to your clothes, you’re probably wearing the wrong thing.
Try to scope out the place before you go to apply for an interview and check out the way employees dress for work. If you live too far away to visit, simply call the human resource department or ask a receptionist. You don’t even have to identify yourself: “Hi, I’m interviewing with your company, and just wanted to know what your dress policy is.”
I'm sorry- is that your tongue ring clicking?
In some companies, piercing and tattoos are okay; in others they aren't. This is another reason why the pre-interview snooping mission (or calling up the company's human resources department) is a good idea. In most cases, though, your best bet is to leave the piercing jewelry at home and cover the tattoos. The fact of the matter is, they can be distracting- which is the last thing you want right now. The focus should be on you, not on your body art. Remember: you're not trying to make a personal statement; you're trying to get the job.