As the meme has grown over on rpg.net, many posters have adopted avatars that featured the Go Play symbol in them. Thomas T. has been particularly prolific in his Go Play designs - here are most of the icons from that thread (till now):

Go Play Iwo JimaGo Play DicePause PlaySuperman Go PlayGo Play Green ArrowGo Play in Traffic

Edit: No way is this post gonna manage to keep up with gamer innovation, but here are a few more Icons: