Quoted:
I love that little doodad, it's awesome!

It would be a huge help if it came in two colors though.  

Red- if you have only read the thread and not posted.
Green- if it's a thread you have posted in.

When I read a thread and don't have anything to add to the discussion (or a smart ass remark in GD) I find myself sometimes later in the day, when I see the green arrow, wondering if I posted anything in the thread.  

The red/green indication would answer that at a glance.