I've come to carrying a money clip on me on planes along with a hot spark. One I was given by an FBI friend happens to be made of coated steel, so I can still use it to strike my flint and I am sure I could get some kind of edge on it if I use a rock as a sharpening stone. Also, I've found that cd's shatter into shards when broken. These can make arrowhead, spearheads, ect. I believe you can still carry a Bic, that is good to have. Some para cord is good to have (I put a coil knot of paracord on my hotspark). Some fishing line and saftey pins would be good, you might even get away with a small sewing kit. A travel mirror, some duct tape, a fresnel lense, compass zipper pull.....hmm, I can't think of any more but those are some ideas. Just don't try to sneak anything, it isn't worth it.