I think that would be really good.
Just to notify people when someone else is typing something than thinking the other person is ignoring them.
Honestly, I like this and think this would be useful. d;
I like this, but I think this would be even more useful to have when you are typing in chat. People see you standing around and are all upset when you don't respond to them, but you are actually having a long IM with a friend. And NO, I do not want some kind of lips icon for chatting, yuck!