They are used to make a green bean casserole, which I think is hideous! Thousands upon thousands of people eat this stuff at holidays and at home. Think you mix the beans with mushroon soup, put in a casserole dish and top with a can of french fried onions around the edge and bake for a while.
Continue to eat the fresh ones as long as you can get them. My MIL taught me to used the canned ones during winter months when fresh were not available by frying a strip of smoked bacon in the bottom of a pan, then add beans half drained and cook/simmer on top of stove about 30 mins. I think bacon makes anything taste better.
Hope this will help you.
delma