I voted naked, but I do use a case when doing rough/dirty work (chainsaw, up on a roof etc). I found this great case at best buy - the Lowepro DMC-Z memory card wallet. It is a very small padded case that zips up completely, offering great protection. I just cut out the middle divider since it wasn't needed.
I'm running the Verizon Shell/Holster combo w. a BestSkinsEver screen protector. I visit construction sites often, so i think this combo will provide good protection