Wordle is a free web app that allows you instantly visualize text works.

ordle is a toy for generating “word clouds” from text that you provide. The clouds give greater prominence to words that appear more frequently in the source text. You can tweak your clouds with different fonts, layouts, and color schemes. The images you create with Wordle are yours to use however you like

For instance, the U.S. Constitution, or the Numa Numa song.