Swiss+Tech ST66676 Utili-Key 6-in-1 Key Ring Multi-Function Tool
I first came across this remarkable stainless steel mini tool in my local Eastern Mountain Sports many years ago while doing some Christmas shopping. Screwdriver, knife and bottle opener in a key sized package? Yessss! I got one for myself and returned a few days later to get one for everyone on my Christmas list that could plausibly use one. I’ve had it on my keychain ever since. I primarily use mine for opening boxes and bottles but the rope cutter and screwdrivers see duty now and then. Note that if you fly a lot you will get this taken away on approximately every other trip, but there is a plane friendly model that swaps out the blade for a file and nail pick.