What's the Most Important Gadget Ever Made?

From the printing press to the personal computer, the radio to the iPod touch, gadgets have changed how we communicate, learn, absorb entertainment, and laugh at nerds. But which was the biggest game-changer of all?

I'll start things off by paying homage to a gadget that changed the world from the mid-15th century until... well, until just a few months ago. I'm talking about the Gutenberg printing press, without which we'd still have to endure the oft-illegible handwriting found in illuminated manuscripts and science students' notes. We may be experiencing (some would say contributing to) the death of print, but good old Johannes Gutenberg had a great run there for the past few centuries. But it's an easy argument that the personal computer is just as revolutionary a gadget as the printing press, and took root far faster. The clock, bicycle, lightbulb, and beer-filled USB drive are all totally valid answers as well.

For the sake of argument, let's define gadget as either a mechanical or technological device from the modern era. Sorry to the jokers who were going to say "a rock!" or "fire!"

As a side note, the first person to say the iPhone will get a personally written Angry Windows Guy message from me, the only exclusive Windows user left on staff. But what say you, commenters? What is the most important gadget ever made?