I have been thinking the same thing... I've read comments that looking at the book the same way that you look at 3D images creates the desired effect. My question, though, is that when i look at the 3D images, i cross my eyes, and see the images inverted. Does this do the same thing for you or should i try to work on diverging my eyes, instead of converging(crossing) them?

If i should work on diverging them, what would be a good way to develop that skill? should i practice looking at those 3d images?

thanks!