Inert devices
Each week inert devices like old hand grenades and toy weapons are found. Of course, they don't know these are inert until a full lock down and examination by the appropriate teams have taken place, like the WWII era bazooka in Chicago. A question to the guys who thought taking a fake home-made bomb to a retirement party in Florida was funny, how was your time in the slammer?
Knives
I once had a pate knife, bought at the airport after my bags had been checked, confiscated transiting through Australia. I was mad. It was blunt and had a cute handle. But the guys at TSA found a sword hidden in a cane in Akron Canton, a double edged comb knife in Detroit, a belt buckle knife in Kansas and a lipstick knife was whisked away in San Antonio.
Suicide Vest
The craziest thing I've read on the TSA blog is the suicide vest that alarmed officers when it went through x-ray. Upon opening the bag they also found electric matches, a bag of potassium chlorate, a bag of titanium powder and a bag of powder that appeared to be a mixture of both. Turned out the owner was an explosives instructor who obviously has a pea for a brain.
If you haven't been to the US since 2010, you'll need to apply for an ESTA waiver. Here's how to go about it.