The facial expression one makes to silently assert one's innocence under the scrutinous eye of an authority figure, typically involing squinted eyes and a large. toothy grin.
CoolFace is the coolest name in the world. It started out as a replacement for the name "Cloud" in Final Fantasy 7 because the originator had thought that "Cloud" had "a cool face". From there, it has evolved to a name used by 1337 Starcraft players.