Visit Inkart. Beautiful site.
Tried to duplicate the effect in PI. You can access the halftone settings if you converted an image to black and white mode. For images to be displayed on the web, a setting of about 20 to 25 produces decent crosshatch patterns. I converted some grayscale gradients to B&W, converted those to grayscale and used them as masks for my main RGB image. A little test run.
http://uploadhut.com/view.php/37216.gif