Nature is exploring new options in scholarly communication with Nature Precedings. As the name suggests this site is for pre-publication, pre-referee research, presentations, and other scientific documents. There is a curation team that checks for relevance of subject matter, but no refereeing is carried out. The site enables readers to comment and vote on documents, and it features the most popular and most active discussions.
A good example from Nature Precedings is "Open Notebook Science Using Blogs and Wikis". This article by Jean-Claude Bradley has comments and votes so you can get a feel for how it operates.
Bradley, Jean-Claude. Open Notebook Science Using Blogs and Wikis. Available from Nature Precedings <http://dx.doi.org/10.1038/npre.2007.39.1> (2007)