Step 1: Position camera, laser, and cylindrical lens
Align the laser so that its beam passes through the cylindrical lens, creating a vertical line rather than a point, and projects onto your target. Initially, the lens was the stem of a wine glass, but in this picture I use a cylindrical piece of acrylic. Position the video camera at a small angle (~15 degrees) from the laser.
Step 2: Position target on rotating platform
Create a platform which rotates at a constant angular velocity. Record players, for example, are perfect for small objects. Position your target at the center of rotation. And make sure your target closes her eyes!
Step 3: Lights, camera, action!
Turn off the lights. To make the image processing easier, it's very helpful to get the room as dark as possible so that only the reflected laser light is visible. Rotate your target at a constant angular velocity. Record the video. Notice how protruding features displace the laser line.
Step 4: Process the video
Convert the video to an avi. Use an edge detection algorithm to find the location of the laser line. Reconstruct your 3-D model. I've included an early, uncommented MATLAB script, which was used to generate this image.