Computer science is evolving blazing fast. On one hand it's hardware that's providing more and more computational power and on the other hand it's software that gives us endless opportunities. IMO if it hadn't been for Open Source and sharing knowledge we would be changing the world in a much slower pace.
So my question is: which other domain could accelerate beyond our imagination if it adopted Open Source model?
Government - massive legacy monolith in serious need of public participation: to build new features, refactor, improve efficiency of the decision-making process, better tracking of performance issues, cost/spending, transparency and accountability. The open-source model seems particularly appropriate here.
Social infrastructure - research, development and distribution of information for alternative/affordable/sustainable ways to build machines, equipment, farming, housing, renewable energy.. Projects to help people improve their conditions in "developing" countries.
Scientific advances from outside traditional contexts like academia and corporations - more ways for amateur scientists and serious hobbyists to build, invent, experiment, collaborate.
Government: I think all democratic nations should adopt open source model in their government. Some countries we can get information through (Right to Information), But that too have limitations. When national budget is made. There should be an open system linked, where anyone can track every single penny being spent.