I have to agree that writing is the most important innovation. First, it lets you expand your own memory. I do not have the memory capacity to multiply two ten digit numbers, but I can handle it easily with pencil and paper. I can manipulate very complex algebraic expressions by using pencil and paper. I can share my manipulations across space and time. But wait a minute. Computers have memory. Computers help me calculate 10 digit numbers and manipulate complex algebraic expressions. Whoa! A computer's memory is just another kind of paper; it is like a big tablet with lots of big pages. And the processor is just a convenient device for writing and reading to the big tablet.
Money (real one, no the fiat paper kind we have now), and free market system.
Money made exchange of the fruit of the labor convenient and easy.
Money made division of labor, specialization and as a result huge increase in productivity possible.
Division of labor made all the inventions mentioned in the poll possible. Without it those few of us alive would still be at caveman level.
Double edged sword indeed! Religion brings out either the best or the worst in people. Most religions are more about men trying to control other men than about God. And they've probably caused more wars than anything else.
Interesting comments, however, I don’t think you are taking the infant mortality rate into account. Your assertions about “more healthy” may simply be a result of the fact that fewer people survived childhood and that those who would have been “less healthy” died early on, thus raising the general health levels of the rest of the population. Some societies did not even name their children until they passed a certain age and celebrated Name Days rather than Birthdays. So, perhaps you should say that you would be willing to trade some of your life-span, provided you made it out of childhood. After all, there is no guarantee you would have been one of the lucky few.