Web 2.0 tools allow the individual to share their interests with others. If someone is an active user of Web 2.0 services, blogging, sharing photos etc, then we can begin to build some sort of a picture of that person's interests. I've been thinking about how one might extend this idea to groups _of people, especially groups with some common interest. Such groups are sometimes called _communities of practice. By definition, individuals within a community of practice already know _some _of the interests of the others in the group - these are the interests which bind them together. But is it useful for such individuals to know about other interests of other members of the group? I surmise that this could be interesting, especially if such other interests turn out to be also shared by a significant number in the group. To this end, I've been experimenting with Ruby, Ruby on Rails, Technorati, and a handy community of practice - namely the delegates of this years upcoming Institutional Web Management Workshop. Having invited the delegates to submit the URLs of any blogs they might happen to maintain, my script interrogates the Technorati's open API and returns the set of tags used by each blog. Next it aggregates these sets, and 'weights' each tag according to how often it has been used across the collection of blogs. Finally, it generates a 'tag-cloud' as a way of visualising this data. Each tag in the cloud links bag to a search for usage of that tag in Technorati, so that other bloggers with a similar interest can be discovered. Because there was some location information available (the post-codes of participating delegates' institutions) I integrated a GoogleMap to show where the 'community' has come from geographically. The results of this experiment can be seen here. If anyone is interested in the underlying code they can contact me directly.