This technique takes regular photos and gives you some very interestingrepetitive, overlapping patterns that I think resemble either tropicalbird feathers, or fish scales, depending on the color scheme.

The procedure is pretty simple. Start with the photo of your choice.The best results are obtained with images that have a lot of color variation.Images with several bright colors in close proximity work well, as do thosethat have a lot of different shades of one color over a small area. Theimage below is part of a picture that I got from ArtToday.
 
 
 

Now click on the Selection tool in the Tool bar. Set the Selectiontype to Rectangle, Feather to 0, and make sure that the Antialias box isUNchecked. Now just choose a narrow, long rectangle from your image - somethingwith a lot of color variation. Usually  I choose rectangles that arelong vertically, but for this image a horizontal rectangle worked best.We can fix that shortly. After you've made your selection, copy it. (Edit:Copy.)
 
 
 

We're going to use the selection as a Fill pattern, so first we needto paste it as a new image to get a copy (Edit, Paste: As New Image.) Igot the image shown below after my selection.
 
 

As I said, I think vertical rectangles work best for this technique,so I next rotated my image by 90 degrees. (Image: Rotate.) I set the Directionas Left, the Degrees as 90, and I checked the box marked All Layers. This is just a personal preference on my part, and you shouldn't feel obligatedto agree with me.
 
 

Next, we open a new file (File: New) with 16 million colors and awhite background. The one I created had a size of 350 x 350 pixels. Thisis where we are going to create our pattern. Choose your Flood Fill tooland set the Fill Style to Pattern, the Blend Mode to Normal, Paper textureand Match Mode to None, and the Opacity to 100. On the second tab, selectthe name of your rectangle pattern from the New Pattern Source dropdownmenu. Click on your new window and it will fill with a repeating pattern.
 
 
 
 

Here's where we create the feathering/scaling. Simply apply a Deformationto your image. I find that Twirl works nicely (Image, Deformations: Twirl.)Adjust the Degree setting until you get a pattern that pleases you. Theimage below was done with a setting of 250. You can see the feathery wing-likepattern appear.
 
 
 
 

To create seamless patterns from your design, first click on yourSelection tool and set the Selection type to Rectangle. Again be sure thatFeather is set to 0 and that Antialias is unchecked. Choose a small portionof your pattern to work with. Remember, your new seamless pattern willbe either 2 or 4 times the size of the area you select. A number of verydifferent designs may be created from the same starting pattern.
 
 

Now open a new file (File: New) large enough to contain your pattern.The one shown here is 200x200 pixels with a white background and 16 millioncolors. First create a new layer above the background (Layers: New RasterLayer.) Then paste your copied pattern as a new selection (Edit, Paste:As New Selection.) Move it down so that there is enough room to paste thepattern again.
 
 
 

Paste your selection a second time and situate it right above thefirst selection, so that the edges just meet. Now Flip the second image(Image: Flip.) The two patterns should now blend seamlessly. Next, useyour Selection tool to draw a large rectangle all the way around your pattern,and then copy the pattern (Edit: Copy.)
 
 

To get your final pattern, simply paste it as a new Image (Edit,Paste: As New Image.)  A pattern such as the one shown below wouldbe suitable for creating a sidebar background. It will tile seamlesslyfrom top to bottom.
 
 

To create a fully seamless pattern, you'll need to open up a largerwindow, something about 350x350. A little extra room never hurts. Firstcreate a new Raster layer (Layers: New Raster Layer) and then paste yourdoubled pattern. Move it all the way over to one side after the paste.Now paste again. Move the new selection right up against the side of thefirst one. This time however, mirror your image (Image: Mirror.) Aftercopying and pasting this new image as described above, you will have afully seamless tile.
 
 
 

Shown below is another seamless tile created from the starting image.This one actually has more of a recognizable feather quality.
 
 

If you don't like how the Twirl deformation looks, try the Wave deformation.It will also give a feather-like pattern. Simply adjust the sliders untilyou get something you like.
 
 
 
 

The example above is a good sample of the feather results of thistechnique, but I also wanted to include a more scale-like image. To createscales, use a thinner rectangle to create your pattern, and choose an imagethat has a lot of variation in a single color. The tile below was createdusing this technique. This pattern is strongly reminiscent of snake skin.