Add another piece to the ever-growing list of Twitter visualizations. What makes Moritz Stefaner's Revisit different is that it focuses on the conversational threads between Twitter users over time. Tweets (symbolized by authors' avatars) are stacked vertically and organized by time horizontally. Tweets that have more attention via @mentions are closer to the middle.
Let the animation play out, and new tweets are expanded with their connections. Last week's beard post, for example, got a lot of retweets:
The downside is that Twitter's API only lets you retrieve tweets from eight days ago at the most, so you can't explore through the archives. However, because you can specify the users, keywords, tags, etc, it's great as a tweet wall for a conference or as something to run in the background on your second monitor.