my sister says it makes her brain hurt, but i like it for its comprehensive representation-value. it's a document containing several models of a different kind of electoral map. see the full document via the link, but to get a sense of what you'll find, the map above "represent[s] the effects of the electoral college by scaling the sizes of states to be proportional to their number of electoral votes." nice.
thanks to Patricia Freitag Ericsson for sharing this on the WPA listserv