FOAF Graphs
Dean Jackson (of W3/SVG fame) created a very nifty SVG graph generator which took XML (or RDF) source and let you explore the space, originally it was the IMDB, but there have since been others. I took the svg, and applied to foaf data with a few simple changes, and have quite an interesting foaf:knows/co-depiction explorer that lets you visualise graphs of relationships within the FOAF world.
The next plan is to improve it so you can interact with a blob, to find out more about them. I also looked at filtering the graph so only people with certain foaf:interests were represented - unfortunately though, there’s not enough data to really do this.