If you live on either coast, or even in the Midwest in a major metropolitan area, you'll have no problem finding an Asian grocery store. Korean-specific markets are a little harder to find, and if you're somewhere where there isn't a huge population of Korean people, well, you might find yourself at a loss when a craving for kimchee strikes. You can make it yourself, or you can click over to koaMart, an online Korean food grocer.
Sure, they do the dry, non-perishable goods like ramen and rice, but they can send perishable goods like tofu and kimchee as well. I've never shopped at the store since I live in Los Angeles, but if I were in say, the mountains of Colorado (or really, really lazy) I might give them a try. Shipping isn't cheap, but hey, when you need your pickled, fermented cabbage, you gotta do what you gotta do.
Remember back when Webvan and Peapod were totally revolutionary, and then suddenly they just keeled over dead with the rest fo the web? It seemed that online grocers would just never work out.




