You could put in a whole weekend perusing these real portraits of Second Life avatars by "Nylon Pinkney", SL name of supremely talented East Coast-based artist Elleinadart. I love how she manages to convey personality and character in her portraits, paradoxically bringing out more life from her 2D lines and colors than the original, 3D digital avatar. (Compare her drawing above left with the screenshot she created it from, above right.) By the way, she creates these portraits by commission.
Here's one of her more recent works, a portrait of famed SL blogger Strawberry Singh: