For those obsessed with tags - and what marketer wouldn't be based on the fact that you want your brand to be a tag as often as possible, and to understand how your content and products are being tagged - check out Wordle. Bringing style to the tag cloud.
Here's one I ran for MarCom Professional just now (click on it or here to see the original), and then a description of 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."