Voting rules: Choose the invention you think is the most useful!
This is a community-based ranking of the most useful invention of the 21st century. We do our best to provide fair voting, but it is not intended to be exhaustive. So if you notice something or invention is missing, feel free to help improve the ranking!
A participant may cast an up or down vote for each invention once every 24 hours. The rank of each invention is then calculated from the weighted sum of all up and down votes.