The story I heard is that Koreans started to use stainless steel chopsticks at the end of World War II because after the war there was no more wood in Korea, but a lot of scrap metal.

They are harder to eat with because things (especially noodles) slip and slide off of them. They're good to stab food with (even if doing that does make me look like an uncouth barbarian.) I've got a chopsticks-and-spoon set that I take around because they are convenient to carry and will never break.