Is it possible to implement some feature that keeps track of the discussions that a user has posted to and stores the current state of those discussions--similar to what happens now, but the user could keep track of discussions he/she has posted to?

It'd just be nice not to have to remember which discussions I had posted in and found interesting. I usually have a bad short term memory and forget I posted just a few minutes afterwards!

Maybe just a little icon on the side of the discussions that indicates that you have posted to that discussion?