Arno Scharl is best known for his book on the geospatial web. He also runs a Web 2.0 content agregator called ecoresearch, which visualizes, in a variety of contexts, research, articles, etc. on climate change and on the geospatial web (although the former is a fantastic implementation, it does illustrate the hazards of not updating content; the latter site is mostly a plug for his book). His article, Media Watch on Climate Change: Building and Visualizing Contextualized Information Spaces, introduces the technology behind the climate change aggregator and does a nice job in describing the ontological and semantic underpinnings of the site.
Their knowledge planet infrastructure is really cool, if only I could figure out exactly what it was showing (maybe it's my browser).
(And they're running off of the same drupal theme--garland--in their content management system as us.)