Years ago I used to carry a kit a little like this but I stopped after only using it to fix paper cuts and other minor things. Now days, with a perceived greater possibility of terrorists and whatnot I might start carrying again.
The smallest yet most useful tools and multi-purpose (think dual-use) implements are the stuff to hunt for. Put your — sometimes expensive — and in any case highly valuable items in an Altoids Mint Tin. The one with the most tools packed and crammed into the standard size — wins. It’s the low-probability, high-impact scenarios that you are preparing for, it doesn’t happen anyway but what if…