The Thanks button is a nice way to show agreement or appreciation for a good post.
Each time you click the thanks button (located in each post), the author of the post receives a point. You have the opportunity to leave a comment as well, which the post author can read.
You can access your own thanks comments in your user cp (click on user cp on the upper nav bar) and the last 30 or so will be displayed in the center section of the page under "Latest Thanks received" You can also see stats about how many times you've been thanked.
When you click the thanks button the person whom you are thanking receives a Pm notification. If you don't want to receive this note, you can disable the notification option in your user cp under 'edit options'.
Note - the button currently displays in the Wrist Twisters v2.0 skin (the orange one).
IMO, if you're going to have this option, it should be on all skins.
I didn't have v2.0 selected.
This thread will sink like a rock.
People will forget about it / not know to they have to change their skin.