My paper describing the mapping between NCBI and Wikipedia has been published in PLoS Currents: Tree of Life. You can see the paper here. It's only just gone live, so it's yet to get a PubMed Central number (one of the nice features of PLoS Currents is that the articles get archived in PMC).
Publishing in PLoS Currents: Tree of Life was a pleasant experience. The Google Knol editing environment was easy to use, and the reviewing process quick. It's obviously a new and rather experimental journal, and there are a few things that could be improved. Automatically looking up articles by PubMed identifier is nice, but it would also be great to do this for DOIs as well. Furthermore, the PubMed identifiers aren't displayed as clickable links, which rather defeats the point of having references on the web (I've added DOI links to the articles wherever possible). But, minor grumbles aside, as a way to get an Open Access article published for free, and have it archived in PubMed Central, PLoS Currents is hard to beat. What will be interesting is whether the article receives any comments. This seems to be one area online journals haven't really cracked — providing an environment where people want to engage in discussion.
