Though it's still early in the polls, I'm quite surprised to see that medicine isn't doing any better than it is. I personally can't imagine any subject benefiting more so than medicine in using an open source method.
Just imagine if medicine weren't burdened by patents and how it could truly benefit everyone. With an open source development method, we could see many more treatment options open up much faster due to input and tests from a much larger group than a single company.