Remember that you can't do like Chrigu and Nate said if you want to add methods from a static class (Hence you can't create any instances of it).
A workaround is to create lambda functions calling the
methods:
// Our static handler class
static class MyHandler
{
    public function getPrice($item)
    {
        $prices = array("apple" => 4, "orange" => 5);
        return $prices[$item];
    }
    public function buy($item, $number)
    {
        $price = self::getPrice($item) * $number;
        do_thing_to_sell_the_item();
        return $price;
    }
}
// Use reflection to get method names and parameters
$mirror = new ReflectionClass("MyHandler");
foreach ($mirror->getMethods() as $method)
{
    // Create new "lambda" function for each method
    
    // Generate argument list
    $args = array();
    foreach ($method->getParameters() as $param)
    {
        $args[] = '$'.$param->getName();
    }
    $args = implode(',', $args);
    
    // Generate code
    $methodname = $method->getName();
    $code = "return {$real_class}::{$methodname}({$args});";
    
    // Create function, retrieve function name
    $function_name = create_function($args, $code);
    // Register the function
    xmlrpc_server_register_method($myserver, $methodname, $function_name);
}