As I learned last spring, smoke detectors are practically impossible to find in Gwangju and Jeollanam-do, and are even tricky to find online. Given the lack of fire safety in apartment buildings, and the unavailability of smoke detectors, perhaps they'll join tampons, deodorant, and family photos as things you shouldn't leave your home country without. I'm not interested in debating the availability of tampons or deodorant in Korea in 2008, but you get my point.
Mike from The Underground Grocers has said he'd order some to his shop in Gwangju, but he would like to get an idea of how many people are interested. If you're in the area or can get to Gwangju easily enough, please reply to the thread on The Underground Grocers Facebook page as soon as possible and tell how many you'd like to purchase. I'm going with four: two for my place, two for my girlfriends'. Might be redundant, but maybe I'd stick one in the main room and one in the hall near the door just in case.