Jer Thorp and Mark Hansen recently have published the design process behind a beautiful infographic (yes, they do exist!) titled "138 Years of Popular Science" [blprnt.com], which was custom designed for the magazine Popular Science (PopSci). With a history consisting of 1,563 issues spanning almost 140 years, PopSci proposed to summarize quite some material in a single visual representation.
The resulting graphic follows the metaphor of a molecular chain, with decades forming clusters which in turn contain clusters that represent years. Accordingly, each 'atom' stands for a unique PopSci issue, which is colored according to the average color values of the appropriate historical issue cover. In addition, the size of each 'issue-atom' is determined by the number of words in each issue. Lastly, about 70 different word-frequency histograms surrounding the main graph reveal the usage of different terms per issue.
If you are still hungry after looking through all these design iterations, Jer calls "dead-ends, messy errors and bad decisions", a poster-sized version of this graphic has been made available for sale.