Eat 'em boiled with butter and fresh black pepper - broad beans are good like that as well... er...IMO.

All you old-hand gardeners who live in long-season places won't be interested in this or already know it, but for more Northern amateurs, there's a neat solution to unripe tomatos (besides using them green). I've done this several times. When you find a heavy fall frost is predicted, and you have plants covered with nice green tomatos, haul the plants right up roots and all. Shake some dirt off and hang the plants roots up in a sunny room. Pretty well every tomato will ripen fully over a few days, with no rotting and none of that hardness you get in some tomatos not vine-ripened.