I just discovered a cool poster-creating applet called Wordle. In their own words:
Wordle 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. You can print them out, or save them to the Wordle gallery to share with your friends.
You can create an image from text that you type in, or from a URL of a blog with an RSS feed. In the latter case, the applet uses all the text it finds at that URL, excluding some common English words (or whatever other language you might choose).
I rather like the result I got by giving them the URL of this blog: