This was my second attempt at creating a stereo pair/stereograph I could view without assistance... (and yes, my cat wouldn't leave the background so the orange blob really is staring at the camera...)

For me to see these, I can do it via the old eye-crossing method. I will get two images (you'd see a pair of both images), then I'll "relax" my eyes until there's a crossover and you see three images, one left, one doubled, one right. Then, if your eyes are in the same horizontal plane, you can slowly start to focus the middle image (the crossed one) and as it comes into focus, it will suddenly gain depth. For me, they don't pop out of the screen, but the image gains a depth so that the near is closer to the screen surface and far is "deeper" into the screen. I'm doing these in "portrait" width because some people can't cross their eyes enough for a wide landscape image. You could also try with a smaller version (see below for sizes) or even the thumbnail (it works).

If you can or can't see the pair (or rather view the pair and make it work), let me know...