I have a blank 12'x12' concrete slab in the corner of my back yard (it abuts an 8 ft tall wall on two sides).
Popular options in the Southwest seem to be a Kiva fire snug in the corner where folks gather for warmth when it's cooler, or building a gas grill with a tile island. I'm not sure how many cook in this scenerio. The latter can be simple (gas grill), to complex (grill, sink, etc.).
I'm debating something different... an assortment of options for cooking. A gas grill for quick eats. A slow grill for ribs, etc. over coal or wood. How about a kiva with room for pizza, or a rotating spit for big meats? Maybe we have 4-5 different coooking scenes. Is there an affordable way to build this? If you know how, I can help you market it - pop me a note.