Wired Magazine reports on a new drug-detection patch under development by SpectRx. "For the monitor to work, employees first have to have four microscopic holes -- about the size of a human hair -- burnt into the outer layer of their skin by a handheld laser... The oval patch houses a miniature vacuum pump that sucks out interstitial fluid, a clear, water-like fluid that surrounds cells in the body.") When a drug is detected, a miniature transmitter sends out an alert signal.

The invasive nature of this monitoring device, along with the steep $300 price tag, leads to the conclusion that few people would *voluntarily* use such a device. Thus the "market" for the device will almost certainly be comprised of people compelled by courts or employers to use it.

Of course, already in use are drug detecting sweat patches (http://www.fda.gov/bbs/topics/ANSWERS/ANS00674.html) which are cheap, but easily removed.

Read more about the patch here:
http://www.wired.com/news/gizmos/0,1452,61158,00.html