Yesterday I mentioned about the possibilities for Twitter but failed to mention a comments feature.
My suggestion is comments for each post (like Jaiku), at the moment you can Direct Message a person to perhaps respond to a particular post, or some people just post as usual with “@name” before the message, which is a bit messy as some of us who don’t follow the person they are replying to don’t have context as we didn’t see the post they are responding to (really, it’s not for our eyes).
Maybe we could comment on a post as a reply mechanism, this comment wouldn’t appear in your user public stream, and people who follow you won’t see the comment (as like before they may not know what you are commenting about).
All people following the person who posted would see the comment, even if they don’t follow the commenter, or the commenter could restrict the comment to just be seen by the poster (similar to a direct message, only threaded).
How would the commands work, you would have to comment to a unique post ID, ie. each post in Twitter eg. http://twitter.com/steverubel/statuses/8002231.
Maybe a comment command could be:
8002231 thanks for the tip
What if you only want the person you are commenting on to see:
D steverubel 8002231 thanks for the tip
Only issue is when you receive an update it only lists the username and the message, it doesn’t list the postID, I don’t thinking selecting reply on your phone or IM will work.
It would be all easy on the web, just browse to the post and leave a comment.
Check out my Twitter Tips and Tricks! post which delves into this topic a little more, especially with the idea of public direct messages.