There is a nice entry on Open Access on the blog of the Electronic Publishing Trust for Development. It starts out:
The only purpose of open access to research literature is to provide the widest possible distribution of the latest research findings to the global community and to enable the development of new knowledge for the benefit of mankind.
The EPT does good work:
The EPT is a UK registered charitable trust, the aims of which are to support scholarly publishing in the developing world and to facilitate access to research information, particularly through open access. Its web address is http://www.epublishingtrust.org.