I've never been able to solve magic eyes, I stare and stare and stare but nothing happens. I've read and been told what you're supposed to do to be able to see the hidden image, but never once seen anything through the image.
I understood the idea of crossing your eyes and figured that I could write something to do it for me, which is what this is. The main problem came when figuring out the depth of the hidden image, so it works for most images although there are some which it can't figure out.
You can input an image (local file or url) and it will load it and process the image to give you what it thinks is the hidden image. Give it a go! There are some test images you can choose from. There is also a slider to move the image, this acts as if you were moving towards to away from the magic eye.