The subject of body jewelry as it relates to airport security was discussed on the Travelite Blog.

This is what it said by way of introducing me as the expert quoted in the article:

One person who would know is professional body piercer Elayne Angel. Elayne is not only covered in various forms of ink and metal herself, but she is also one of the pioneers in professional body piercing, a field she personally helped expand decades ago. Elayne has served multiple terms on the board of the Association of Professional Piercers as an advocate for field safety, and her most recent project has been authoring The Piercing Bible, the definitive guide for consumers and professional body piercers.

Check it out. There's lots of great information througout the site, and if you travel, be assured you'll find plenty of great tips and ideas.