We are developing an interaction technique for rich nonverbal communication through an avatar. By writing a single letter on a pen tablet device, a user can express their ideas or intentions, non-verbally, using their avatar body. Our system solves the difficult problem of controlling the movements of a highly articulated, 3D avatar model using a common input device within the context of an office environment. We believe that writing is a richly expressive and natural means for controlling expressive avatar gesture.