I know one of the plug-in packages has a halftone effect (like an old newspaper photo) which is what I think you're after. You might try playing with converting the image to indexed colour too (has to be converted to greyscale first) this will make all pixels solid black or white - no greys so it would only work on B&W images. Though you could try colourizing them after you've achieved the effect you're after. Hope this helps! Baz