Google fails me.
EDIT: Damnit, there's no good way to explain this.
It is a giant yellow smiley face. Used all over to express a "HE HE HE" sort of happiness. Often used in snarky posts of SF_Drama or the sorts. Its eyes are looking to the left. It has a :D mouth. I'm not insane. Really.
Can ANYONE link me to this?
What's made you happy today?