Here's a writeup of Evan Booth's Hack the Box conference presentation on making lethal weapons out of items bought in airport duty-free shops. It's pretty ingenious stuff (the video above is from a related presentation at CarolinaCon 2013).
The problem here is that legitimate purpose of airport security is not protecting passengers and flight attendants from harm. In reality, there's no way to accomplish that goal against a determined attacker. The real and legitimate purpose of airport security is to protect airplanes and cockpits from harm — to stop people from hijacking and/or crashing airplanes (this is why the TSA correctly relaxed its rules about carrying small knives onto planes — and why so many of their other rules are pointless and stupid). So long as none of these lethal weapons can crash an airplane or beat an armored, bolted cockpit door, they embody no new incremental threat to aviation — on the other hand, the improvised battery-bombs are a real threat.
Besides a bomb knew Booth also easy to make a bow and arrow of stuff he had bought in a shop in an airport. For this he used an umbrella, hair dryer, socks, a leather belt and condoms. Too obvious things like a lighter and deodorant as alternative gas burner he did not elaborate.
Booth also made a crossbow of an umbrella, floss, grab a toy, a rolkoffertje, a straw and tape. With a straw, cotton and a piece of metal from a remote controlled helicopter he was able to make a blow gun for firing arrows.
Remarkable is also a club that he made a gift, what magazines, floss, a leather strap and tape. In a test showed that so firmly, that he with a single blow a coconut in several parts stores.
Onderzoeker maakt bom van artikelen luchthavenwinkels [Dutch, Nu.nl]
Researcher makes bomb Articles airport shops [Google Translate]
(via /.)