Forbes has compiled a list of the top 20 tools of all time. The top 5 are:
1) The Knife
2) The Abacus
3) The Compass
4) The Pencil
5) The Harness
The scary thing is that 3 out of the top 10 are, or can be, weapons.
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"The future is here. It's just not widely distributed yet." -William Gibson
What about the lever, the wheel, the inclined plane, the hammer? I guess when you pick an arbitrary set of criteria you can get arbitray results. Don't get me wrong the tools presented are important but most important?