I guess I've become a troll, just subscribing to these lists to see if anyone will ever implement what I need n-ary data to do.  I don't really know how to program anything, but perhaps this comment will be welcome anyway.

There is an amazing new tool for visualizing tabular data called Circos
http://mkweb.bcgsc.ca/circos/?Visualizing_Tabular_Data 

To see the shorter write-up that demonstrates what a cool tool this would be for SMW people, check out this blog post
http://flowingdata.com/2009/04/21/visual-representation-of-tabular-information-how-to-fix-the-uncommunicative-table/ 
It's got lots of pretty colors and does of a good job of selling this new technique.

Robert