Sometimes the camera and kite are stable enough for two images to be almost identical, and by just being a couple of feet apart when taken you can create a stereo pair. Whilst some people have special rigs with two cameras I have relied on the fluke approach, as illustrated here with a picture of Blackness Castle, taken on 27th May 2004.
There are various ways to view stereo images, three are illustrated below. The first is the parallel view. The right eye views the right image, the left the left, the disadvantage is you can only view a small image, but it works without any coloured glasses, you just need 2 eyes.
Look at the blue dots above the images, relax your eyes until you see 4 dots, then concentrate to make the two center dots merge into one, leaving three. The image below the center dot should become three dimensional:

Depending how close your eyes are together (I'm serious!), and your screen resolution, you may also be able to view this larger version, but it is more difficult to see. If the blue dots (as seen on your screen) are further apart than your eyes then this wont work.

Another viewing technique is the cross view where the right eye views the left image and the left eye views the right image. This allows bigger images to be viewed. The viewing technique here is to put your finger between you and the screen, focus on the finger then try to let your gaze fall on the central image in the distance:

All these images are un-cropped from the camera, but have much reduced resolution. For larger images (and resolution) you need special equipment for viewing. The simplest of these techniques is called anaglyphs, you need to wear red/green (to be correct it's red/cyan) glasses. You know the ones - made of cardboard, associated with 1950s Science Fiction films, and make you feel very self conscious. This final image demonstrates what can be achieved with this technique.

The left eye sees the red component of the left image, the right eye sees the green and blue components from the right image. The resulting image is therefore a composite from both images. The human eye has poorer colour vision than greyscale vision, so unless the picture has highly saturated colour areas, your mind fills out the missing information.

May 2005
Another very smooth day resulted in this pair, at Granton Harbour, on "Boat
Lift in Day".
I suspect the crane moved between shots, it is certainly very difficult to
resolve the jib at the top of the picture.

May 2006
Hopetoun House, looking east to the Forth Road and Rail Bridges