I often fly with a travel-size guitar (one of these: http://www.guitarbench.com/Images%20for%20articles/brunner/8.jpg http://www.guitarbench.com/Images%20for%20

I often fly with a travel-size guitar (one of these: http://www.guitarbench.com/Images%20for%20articles/brunner/8.jpg http://www.guitarbench.com/Images%20for%20articles/brunner/8...). The neck comes off and it packs into a case that's small enough for carry-on. It has often struck me that a guitar neck with six metal strings attached would make a fairly effective weapon (at least, by TSA standards!) but I've never had any trouble getting through security, apart from occasionally having to put it together.