I have a mate that regularly carries one of those small folding saws for trail debris clearance. One year he was flying to Greece and taking his bike - he had his bike rucksack as hand luggage and hadn't repacked it! His bag was seized at security and he was marched to a little room. One member of the travelling group was in charge of the IT for that same airport. The IT companion didn't step in as a character reference or acknowledge he knew him! Amazingly the police accepted the guy's his story and he made his flight!I only took it to deter the dog.
The oddest thing I take with me on a regular basis is a folding saw.
Highlander Wolverine Folding Saw Green
I have a legitimate reason for carrying it, but given the subject matter of this thread, it is not a quick draw device as it is in my backpack.