Berkshire Hathaway Letters (1983-1987)
A word cloud is a visual representation of a group of words, with the size of each word weighted to how many times it appears. The above two examples use the Berkshire Hathaway shareholder letters for the 5-year periods ending in 1987 and 2007. You can see some often-used words between the 20-year period: business, earnings, value, company, insurance. Word clouds are a good representation of what subjects the author is focusing on.
Below are a few more examples: (all created at Wordle)