We've all had the same problem. You're about to leave the house, but you don't have room in your pocket for a pen, a level, a ruler and a pair of screwdrivers. What if you suddenly need to measure ...

I had about a dozen multi-tool pens in grade school. I had pens that fired lasers and told time and wrote in invisible ink, but for the life of me, I can’t remember using any to actually write ...