Originally Posted by
Jasper2009
Not very convenient for discussions that involve more than two people IME.
Let me add a fourth requirement: "replies/comments should be displayed in chronological order."
Email is very convenient and I use it daily for conversations with much more than two people.
Additionally, any decent email client will display replies in the order that they were received. Now whether the people replying choose to top post, bottom post, or inline post is entirely up to them.
That said, there's also Telegram (didn't see that mentioned).
Also there is IRC since you mentioned being a dinosaur