On Friday, November 21, the Bill & Melinda Gates Foundation adopted an open access policy that applies to all research funded by the foundation. The policy will take effect on January 1, 2015. The foundation is one of the largest grantmakers in the United States. The policy applies not only to the results of funded research but also to the research data itself. See more here:

http://www.gatesfoundation.org/how-we-work/general-information/open-access-policy