Visualization of graph data is incredibly challenging, particularly when it comes to extremely large, scale-free graphs and social networks. A few simple searches on the Web and you will find some mesmerizing and very cool images. Perhaps the most cited...
Status/presence indicator like in Jabber/IM-Apps, but web-based. Nice gui, including display of friends etc.; integrates with Jabber/GTalk and SMS. Company seems to be an Odeo-spinoff.