It'd also be good to have one where you can mark it as "read later" or something. I often see threads that interest me, but 3,4,5 at a time so I read one, but then lose the others on the super active convos and with a memory like mine you forget the titla=es easily.
I suppose a bit like watch this thread but abit less permanent.
If you right click on threads as you see them in active convos you can choose to open them in a new window, or new tab if you have tabbed browsing. Then you can go to them as you finish with the previous one (remember to refresh before you post though in case they've moved on!)