Simple PHP Class for Screenshot'er API http://www.screenshoter.com/
Screenshot'er is the quick and easy way of taking screenshots of any website. You can even select which device size to use, great for demonstrating responsive web design.
/* Take screenshots of PHP.net */
require_once('screenshoter.php');
$website = 'http://php.net/';
$path = './cache/'; // save here
$screen = new Screenshoter($website, $path);
$screen->format('png');
// First: Desktops
$screen->device('desktop');
echo $screen->shoot('desktop.png')."<br/>";
// Second: Tablets
$screen->device('tablet');
echo $screen->shoot('tablet.png')."<br/>";
// Third: Smartphones
$screen->device('smartphone');
echo $screen->shoot('smartphone.png')."<br/>";