The Public Library of Science (PLoS) publishes a number of very well-respected open-content journals, although their work is all in biological sciences. PLoS is one of the leaders in the movement to open-source research. And the venerable arXiv.org pre-print archive has been around for over two decades, offering pre-prints of articles primarily in physics, math, and computer science.
Journals are definitely a barrier to free access to research findings, but the academic community is rapidly questioning why, in the age of the Internet, they are still giving publishers their work for free and letting them make money from it.
