Every survival toolkit needs a good chainsaw, but if you happen to have
some spare parts laying around, why not try creating own pocket-size manual
Instructables user machoturtle says that all you need is an old chainsaw replacement blade, a garden hose, gorilla glue, and a couple saws to cut down the blade. Once you've obtained the needed items, saw down the replacement blade to a pocketable size, glue pieces of the garden hose on as handles to protect your man-mitts.
Now you have nice a tiny little manual chainsaw you can take with you everywhere. Just make sure your kids don't mistake it for a badass skipping rope. Head over to the full guide for the step-by-step instructions.