For me– and maybe this is because I have an overly simple understanding of the concept of “visual rhetoric,” especially as it relates to writing instruction– few things explain how using slightly different visuals can make a big difference in meaning than maps. For example, in my English 328 class, I have a bit of discussion about this with different maps of the 2004 election, different versions of the “red/blue” states from the 2004 election– basically, this site right here.
Now another potentially interesting tool I found via boing-boing, Worldmapper. Basically, it’s a collection of world maps based on all kinds of cool things– population, tourism trends, railway use, moped owners, etc. Neat stuff.