i would guess that the chance for damage far outweighs the benifits. since the click wheel is not part of teh outer casing a liquid can get to the innerds of the ipod through the seam around the clickwheel. if u must paint it my GUESS would be a light layer of spraypaint (hold the can far away and tape up EVERY other serfice of the ipod)
I'm planning on taking iPod apart to paint it. NOT just tape up stuff. There's not really a chance for things to get in there if I just take the entire click wheel off
well if your taking it apart i guess you dont have to worry about the paint voiding the warentee. well my only advice is to take it apart slowly and carefully.