1. Open up Photoshop and go File>>New set the mode to RGB and make it 256x256. Now fill the background with black and make a Rectangular Marquee selection 200x200. Now create a new layer and fill the selection with white on the new layer.
2. Now go Filter>>Noise and add 10% Uniform and Monochromatic. Next chose Filter>>Blur>>Motion Blur and chose Angle 25 and Distance 3. Now go Filter>>Render>>Lightning Effects and chose these settings or something you like.
