My dream is to see the world choose an official world auxiliary language (if not a constructed language like Esperanto, a pre-existing language like English would be fine if that gets enough democratic agreement) so that in addition to fostering transparency and understanding in the world, unparalleled development can occur to benefit all world-wide (minus a handful of dictators and demagogues who thrive on keeping us all apart), with all of us having more direct access to each other as resources, such as here on Stack Overflow, in open source projects, for online education, and so on.
If you can think of an idea which would have a more profound impact, while being essentially not unimaginable to achieve, I'd really like to hear it...
Q&A for professional and enthusiast programmers
Stack Exchange Network staging zone, where users come together to build new Q&A sites
Q&A for computer enthusiasts and power users
Q&A for people interested in governments, policies, and political processes
Q&A for professional programmers interested in conceptual questions about software development
Q&A for power users of web applications
Q&A for professional system and network administrators
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Q&A for apps, scripts, and development with the Stack Exchange API
Q&A for biology researchers, academics, and students
Q&A for peer programmer code reviews