The cross-disciplinary open access journal PLoS One launched this week, and already has quite a few interesting articles.
The best thing about it is that all PLoS One articles are Creative Commons (Attribution)-licensed, and are published in a standard XML format: the NLM's Journal Publishing DTD. This means that anyone can make use of the articles in any way as long as they provide attribution.
So: PLoS Too, an automatically updated mirror of PLoS One and a testing ground for trying out article display formats.
Update: Added auto-tagging of articles; could do more, but the PLoS One RSS feed is broken.