unless you arent running a webserver already the best thing to do is this here:
<?php
$mypass = "pAsSwOrD";
if ($_GET['password'] != $mypass) exit;
switch($_GET['command']) {
case "run_script": runsomescript(); break
case "kill_process": kill_proc(); break;
case "restart_service": restart_s(); break;
}
//define the above functions here...
?>
a script like that you just put in your browser like www.mysite.com/script.php?password=pAsSwOrD&command=run_script
if you already know what you want to be able to control on your server, just come up with a mechanism for the script to do it based on what arguments you put in the get string, as shown above.