Hi Greenery. I wear all-lace units, but sometimes with a thin-skin strip around the perimeter. I can't be sure what I was wearing when I went through the scanners. I don't wear units with poly horseshoes any more.

The idea of smuggling stuff under a toupee has already been done, although thankfully with dope rather than explosives - http://www.boingboing.net/2005/08/07/dru...under.html.