This looks interesting.....
The FUJIFILM WCL-X100, a wide conversion lens made in Japan and designed specifically for the award winning FUJIFILM X100, attaches directly onto the camera and increases picture taking versatility by multiplying the fixed focal length by 0.8x, converting it from 23mm (35mm equivalent) fixed focal length to a 19mm wide angle (28mm equivalent). The WCL-X100 delivers superb optical quality and maximizes versatility of the FUJIFILM X100 by ensuring comparable image quality even at the f/2 wide aperture setting, all while retaining all the original optical characteristics, including the attractive bokeh effect.
The FUJIFILM WCL-X100ís optical construction uses four premium glass elements in three groups to keep aberrations minimal, and also employs the unique FUJINON Super EBC (Electron Beam Coating) for outstanding results.
Fujifilm creates wide-angle adapter and firmware v1.3 for X100: Digital Photography Review