AFK Icon or Message?

Lenora_Pyre - Dreamweaver

Not sure if this has been mentioned or not, but I really, really wish there were something simple to signify being AFK. I've seen there's an auto-reply option, which I assume could be used as such to let people who try to message you know that you're AFK, but it'd be nice if there were an icon to appear over your character's head, too. It should also appear in the Friends and Faction menus, and should be really convenient to activate in a hurry.

I know I'd be a lot more social in this game if I didn't always have to second guess if someone was there or not. O.o