Bill Zeller, a PhD student at Princeton, sent me the link to his project "graph your inbox", that is an attempt to visualize the "data" in your Gmail account.
Seems to me that it acts as a sophisticated "search my mail" engine. The most interesting part is the ability to click on a point or a bar in one of the charts, and have the corresponding emails show up in the preview panel. This interactive ability is also available in the modern commercial graphing packages, and they are extremely useful for data exploration.
Technically, this is a compelling achievement. The amounts of data being processed, organized, summarized, plotted.
I think he needs to figure out some compelling use cases for something like this. Can you help? How would you use this capability if it is available?