I don't use digg but they've launched a couple of interesting real time information visualizations for the stories that get collaboratively selected: Stack and Swarm. I can't do justice to Stamen Design's beautiful work with a text description, but they have surface slickness if not demonstrable long term utility.
Interestingly, the digg labs site threatens to release a public API for the data feeding these visualizations.
[Via Waxy's Links]