Here is the simple way to create many strokes to an object ( without creating multiple objects ) using appearance panel in Illustrator CS3.
First create the object or path you’re about to working on, apply stroke color and then open the appearance panel - Windows > Appearance. Now with the previously created object selected, go to flyout menu of the appearance panel and choose Add New Stroke. Now you have 2 stroke on a single object and you can change their color and stack anytime you want directly from Appearance panel.
