A brilliant periodic table of visualisation methods.
This is an interesting taxonomy of visualisation methods, but most interesting because it practises what it preaches: a good visual metaphor to structure a lot of data, plus clever use of HTML and JS to pack an enormous amount of information into one page.
It is based on a lot of theroetical work, eg on the effects of different types of visualisation , the concept of visualisation generally, and a structured analysis of their periodic table taxonomy and why each method is allocated as it is. Also available is an overview of mapping tools.
The visualisation project seems to be run by several Swiss academics.