That's an interesting idea, but I'd hate to see the miniscule amount of stuff that would come out of that pen. There were some threads awile back on making a micro-kit, they discussed using vacuum packaging to make a tiny kit in about the 1 ounce size range that still have a useful assortment in them. They are also small enough to be at least as easily carried as a typical pen. Mine has a compass, mini-lighter, rubber-band tinder, whistle, razor blade, bandaids, birthday candle, fishing hooks and line, needle, paper clip and retro-reflective tape. It has about the same bulk as a Zippo ligher, is waterproof and floats. It can be easily carried in a shirt pocket or on a neck lanyard or be pinned into a swimsuit. For the smallest kits, there is a real advantage to to using vacuum packaging instead of a rigid container.