I really do need a boxcutter at book signings. I keep the boxes sealed until I get there, because balancing a tower of book boxes isn't easy - and making a tower of open book boxes isn't possible!
When I just threw my box cutter into my teaching box, I always wasted a lot of time hunting around for it. So, I made a little holster for it out of two old file folders. :) Hopefully I remember to put it in there when I'm finished, and I don't just lose it, again.