This is precisely why I built http://tweetsaver.com ... I wanted a nice way to search through ALL my old tweets AND keep them around. I'm always retweeting awesome content, favoriting interesting things, and sometimes I just want to remember what I said without having to click MORE MORE MORE MORE for 100 pages to find it on twitter.com. Maybe someday Twitter will turn on a feature that kills my app, but for now I think it's the best way to archive, organize and search the great content that flows on twitter.