Medicine 2.0 is a weekly blog carnival which collects the most interesting posts about Web 2.0 and Medicine. The latest edition is posted here.
Past editions and future hosts can be found on the blog carnival index page.
According to Wikipedia, "Web 2.0 is a trend in World Wide Web technology, and web design, a second generation of web-based communities and hosted services such as social-networking sites, wikis, blogs, and folksonomies, which aim to facilitate creativity, collaboration, and sharing among users. "
Image source: ScienceRoll, a Creative Commons License.