This tutorial is intended for Photoshop. Image of YoungWoong is from dbsg@livejournal.com.
Images hosted at Image Shack.

Step oo1. I will be using this image of Youngwoong for this tutorial.
Open an image of your choice in photoshop.

Step oo2. Select all and copy. Now create a new document and hit paste to
create a copy of the above image (or the image you chose).

Step oo3. In the duplicate document, go to

image > mode > grayscale and click ok to the menu. Now, go to
image > mode > bitmap and click ok on that menu. On the sub menu
enter in the same number that is in imput. In my case, it’s 72.
In the method, choose halftone screen. Click ok. On the next menu,
you can leave the numbers as they are, or adjust them. In the shape dropdown menu,
pick one of the choices. I chose Diamond. Your end result of that will look something like this:

Step oo4. Select all and copy that bitmap image. And in the original image (the colored one),
paste that in as a new layer. Set that bitmap layer to soft light. Your
end result will look something like this:

You can use this technique on all different types of images.

The End.