We eat them all the time, and love them.
I buy a 1-pound bag in the freezer section (1 pound of edamame in the pod), for about $2.50. Perhaps those who live in soybean country will find them cheaper.
You bring a pot of salted water to a boil, toss in the frozen pods, bring it back to a boil and boil for 2-3 minutes. Drain in a colander, sprinkle the pods with salt, and serve in a big bowl, with another bowl beside it for the discarded pods.
To eat, you pop the shells open and suck out the beans, which are green and tender. (If you cook them a lot longer than I described, the bean will get mushier, and it isn't quite as fabulous, in my opinion).
It does look a bit like a smaller lima bean.
I must say I don't care for peas or limas, but I love edamame. Go figure!
We serve this as an appetizer, and the kids love it too. You have to do a little work to get your beans, so it keeps you from eating 100 chips in a row, which is no work at all!