I was recently pointed to @miljoshi‘s blog and a post on twitter word clouds (using Wordle, of course!). My twitter background was made using Wordle from a sampling of text from my blog. Tweetstats offers the ability to create a Wordle cloud automatically from your tweets, which is fairly cool. Mine is below. It’s dominated by twitpic, since I frequently use it for posting pictures.
Update: Here’s my wordle after removing some words that don’t reflect the content of my tweets as much (e.g. good, great, new, old, etc.). Good idea, Melinda!