I have carried one of these little knives on my keychain forever. They are so helpful, especially the scissors. Once you start carrying one, you can't be without it.
These little Victorinox pocketknives are a mans best friend. I can't recall the number of times it has been used. i.e., cutting strings, opening water bottles (the pull rings have a tendancy to break off), snipping off threads, and tightening screws on chairs. It's small size doesn't "put-off" people. I don't feel completly dressed without it.