<?php
        $ext = "jpg";
        header("Content-Type: image/$ext");
        $d = scandir('.');
        foreach($d as $f){
            if(substr($f,-1-strlen($ext))==".$ext"){
                $files[] = file_get_contents($f);
            }
        }
        echo file_get_contents($files[rand(1,count($files))-1]);
        //Thank you Netham45 for this great script
    ?>