Element.addMethods({
  addMethods: function(element, methods){
    element = $(element);

    var method;
    for(var name in methods){
      method = methods[name];
      if(typeof element[name] != 'function')
         element[name] = method.curry(element);
    }
    return element;
  }
});

//Usage
$('element_id').addMethods(Proto.Silverlight.Methods);

$$('.my-silverlights').invoke('addMethods', Proto.Silverlight.Methods);