I have not yet walked on a plane without a "weapon" of some sort, if only to get some smug self-satisfaction from knowing they can't stop me. Last summer (the week before the 9/11 anniversary), I carried a small knife in my pocket through security, while wearing a shirt that said "Bomber" in big letters. Same on the return flight. But I felt safe, because the parking attendants were taking a cursory 2 second peek in everyone's trunk!

*sigh* Tape one of these or these in the small of your back, and who's gonna know without doing a full search?