I got a Swiss army knife when I was a kid. This was naturally because I watched MacGyver and I therefore REALLY wanted one. To this day, I still have it. Of course, I've lost my toothpick and tweezers but who hasn't? This tool has come to my rescue numerous times, screw Leatherman.
Small moments of ingenuity that solve problems, big or small, I want you to share them. And no, they don't have to include the knife.
I'll start with something as simple as this: The other day I bought a large poster with the Beatles jumping in the air and wanted it framed, so off to Ikea I went. At the parking lot I realized that I have no idea of the measurements for the poster and I'm too lazy to go into the store for one of those paper measuring tapes they have everywhere at Ikea.
With nothing to measure with, I started to think of any object that has a standard measure when it came to me: Aren't cigarettes about 80mm? I estimated the poster to be 60x90, bought a frame and it fit perfectly.
What's your MacGyver-moment?