Hello,
I think this feature would be useful for people who spend lots of time in the Chatter, especially when browsing through Art Sales.

Similar to what is found on ToyHouse, it would be an option to hide a thread. There would be a button on the thread that just says "hide", you click on it, it may ask for confirmation, and then, you won't see that thread anymore.
Alternatively, there could be a way to permanently mark a thread as "seen" or "read" even if the thread gets new replies.
This way, when browsing through Art Sale threads or anything else, you can hide/mark threads you are not interested in, and only keep the new threads you didn't visit yet, or the ones you are interested in.

As an avid art buyer, I open every shop in the 2-3 first pages of the forum, because I really cannot remember the names of every thread.
It would be very convenient to be able to hide the threads I'm not interested in, to only open the ones that I didn't see yet.

This would probably be interesting in other forums as well such as studs.