Wordle*, a Java-based word cloud maker, is described by the designer as "a toy for generating 'word clouds' from text that you provide." The nice thing about this online toy is that you can customize the font, layout and color schemes with a variety of interesting choices.
Here's one I made with a scene from Stay the Night (click on image to see larger version):
This can also be used as a simple visual tool for identifying frequently-used words in your text, because the more you use a word in the text that you feed to Wordle, the larger it appears in the cloud.
*Link found over at Elizabeth Bear's LJ.