All very interesting. But ...
My carry-on usually contains enough stuff to start a small electronics store: Cell phone, GPS, camera, iPod, flashlight, and sometimes a regulator and sometimes a VHF radio. The only time anyone ever wanted to look at it was a TSA agent who was a diver and wanted to compare gear and talk scuba. I regularly complain that if I saw on the scanner the profile of the stuff I carried, I'd want to look at it by hand. They tell me they can identify it as being legitimate. Go figure.
In about October, 2002, my wife traveled from Missouri to California aboard a commercial jet and needed to transport a .45 pistol. She called the airline in advance to check on the protocol. They told her it needed to have a trigger lock and be in a carrying case and to just let them know at check-in. She complied and told them at check in. They examined the trigger lock, put a big sticker saying "firearm" on the case and then asked if she wanted to ship it through or carry it onboard. When she said it was valuable (military academy class pistol), they suggested carrying it and walked her past security with it. No Big Deal. Go figure.