Nature Does Not Require Authors to Assign Copyright and Encourages Poscript Archiving
Source: 11. Copyright and licence to publish. Nature publication policies. Nature (last viewed 19 March 2005) [FullText]
"As of January 2005, authors of original research papers published by Nature Publishing Group (NPG) will be encouraged to submit the author's version of the accepted, peer-reviewed manuscript to their relevant funding body's archive, for release six months after publication. In addition, authors will also be encouraged to archive their version of the manuscript in their institution's repositories (as well as on their personal web sites), also six months after the original publication. This policy has been developed to extend the reach of scientific communications, and to meet the needs of authors and the evolving policies of funding agencies that may wish to archive the research they fund. It is also designed to protect the integrity and authenticity of the scientific record, with the published version clearly identified as the definitive version of the article."
Source: Author License Policy: Nature Publishing Group announces change to self-archiving policy. Nature (last viewed 19 March 2005) [FullText]