I'm sure I've posted this before, but my whizbang survival item is a large cotton bandanna, orange or yellow, dry HOT ironed and folded to pocket size with the iron, slipped into a sterile Gerber Breast Milk bag and sealed flat. The bag edges are protected with Gorilla tape and about ~40" of flat folded Gorilla tape is attached to the bag. Its a bandage, torniquet, chest wound seal, signal flag, dust mask, repair tape and handkerchief, all in one. I carry at least one on my person and more in my EDC pack. Not original but super useful and it never hurts to repeat old but good advice.

Oh wow, so many ideas. I thought that water pureficator is the most innovative thing in my kit

Spare contacts. Tiny space - Very useful.

Ignition pliers are tiny slip joint pliers that weigh almost nothing. In conjunction with a multi tool you can do a lot of jobs that require two tools.