Often I write a tweet and get many replies, and I start a few conversations. I might do this to get some ideas about a blog topic, for example, and feel out what others think about it. In a sense I'm building a reply thread, but I don't have any way to review it later, besides darting around in my mentions view. I'd like to view everything on this topic, i.e. everything rooted at that one tweet, easily.

Unfortunately the Twitter API doesn't yet let you search for tweets based on what they're in reply to. So @atebits can't make a feature whereby you pick a tweet and get all the replies to it, and have those replies cascade into a tree of replies. It would be awesome! But the current API doesn't let developers do it.

But! I would love to be able to do this with my own recent tweets. Those tweets are already in my timeline, and so are their replies, and so are my replies to those.

Here's the idea: Tweetie-Mac could search its own local storage of my tweets and mentions, and put together a reply tree that is limited to my timeline + mentions. That would be enough to show conversations between myself and strangers, and between myself and my friends, in recent history.

I think it's doable without any additional Twitter API calls, and when Twitter's API does support it (there are plans: http://code.google.com/p/twitter-api/...), it could be extended to all tweets for all time.