Need object to move along Conveyor Belt

[21667-unity±+conveyorbelt.jpg|21667]I have simple cylinders going around in circles that pose as rollers for a conveyor belt. How do I get an object to sit on top of these rollers and move along with it? Any help is greatly appreciated. Below is the code for the rollers.

var speed = 5.0;

function Update () {
	transform.Rotate(Vector3.up * speed * Time.deltaTime);
}

A simple way to do this would be to have a trigger volume slightly above the cylinders. If an object enters that volume you could then apply a force or translation in the direction the rollers are spinning.