Keio University's robotics group have demonstrated a set of remotely-controlled facial elements designed to be worn as rings. These could be directly controlled by the wearer, or could be remotely controlled by a piece of software that was portraying a character that inhabited your hand like a sock-puppet or Senor Wences.
"First of all, this device resembles a toy. So we want to make it more like a character, like when children or their parents play finger games. That would enable a new form of interactive play. We'd also like to incorporate this robot into the way children use their hands to communicate with each other."