In my urban location, would have to go with the multi tool, though I would feel funny not carrying a pocket knife.
My best friend's wife once wrote on the calendar in red ink when she asked me for my knife, and I didn't have one on my person. <img src="/images/graemlins/blush.gif" alt="" />
It was rather unusual, and I don't think it has happened again- <img src="/images/graemlins/grin.gif" alt="" />