US Homeland security, in an effort to make "screening" faster came up with this millimeter ray scanning device. If you remember the movie "Total Recall" and the full body scan shown in that one, this looks like a prototype. Most people who are concerned about their privacy have objected to airport security body scans. There are claims that the scanner is "remotely reviewed" by a person who 'cannot' view the face of the person being scanned. That doesn't make people feel any safer. This is not entirely new, you could find a British prototype (I haven't flown there recently though) showing the use of a full body scanner. Here is news of installation of such a device at Heathrow. This body scanner looks identical to the American one shown above.
The same time, I see another Slashdot story which shows An anti-hijacking safety bracelet. The invention is from a Canadian company from what I read. This is akin to wearing a taser that you let someone else operate to ensure that everyone in an aircraft is safe. Here's a video that's got lots of hit demonstrating the usage. That video is straight out of a 1984 / Big Brother movie.
After the 1972 Munich Olympics, in 1976, a Singapore Inventor Sai Kheong Kwan and a former Vice-Chancellor of the National University of Singapore proposed a device, that is similar to the Anti-Hijacking Safety bracelet listed above. Not much information on this invention is available on the Internet. I've made a sketch from a 1982 edition of the Readers' Digest book - "Inventions that Changed the World" from "Inventions that haven't yet made it." You can check the sketch here.
Many of these devices give a false feeling of security while actually igniting totalitarian interests in state administration. Attempting to control and know every aspect of the life of people within its territory has been employed by many governments in the name of security. The results have always been grim and unsuccessful. Increasing airport screening and security beyond a level of reason does not entirely drop the threat of terrorism. In India, prior to the 9/11 event there have frisking and hand baggage checks mandatory. In addition, if luggage stowed contains something suspicious, the passenger's name is notified on another list. I believe that this information is sufficient for most purposes. It is usually "reporting" and "response" to an incident that has been lacking. These heavily restrictive and inconveniencing preventive measures take us nowhere.