Of course you don't want to replace tools...they are expensive and that goes without saying. I sense that you really don't like thinking what you're thinking about the people that were there when you last remember having the tool... this is where my heart goes when my head takes a break from trying to solve the mystery of the disappearance. Some things that have worked for me in similar situations: "Decorating" tools with bright stickers that can't be missed or ignored...no name but definitely identifiable, Being one of the first to gather up for packing, Asking the entire group to help me keep up with my tools since I've been misplacing things so often of late, Setting example by always asking before using someone's tool...use their name when you borrow it and when you return it and make sure (without being obvious) that others hear you, and not having more tools out than necessary at any given time. I just know that I feel better when I don't make it easy for others to do what they shouldn't do...they make it so uncomfortable for those who happen to be around when they mess up. I hope this helps, but even more, I hope you're never put in this position again.