ootweet is a beta site that allows you to archive your favorite tweets and even Twitter discussions. It also has voting on the tweets to help give them rise on the frontpage, much like Digg would for articles. Authentication is via oAuth and let me right in.
I did like the fact that they have a bookmarklet to make adding to ootweet simple. The downside, if you didn’t guess, is that you must use the Twitter web interface an open an individual status/tweet to use it.
Some categories allow sorting, such as clash, fail and joke. The avatars of everyone in the discussion are also shown as well as the flow of Twitter names that participated. Recent users of the system as shown at the bottom of the page allowing you to click through to see the discussions.