Check out drought-resistant lawns. Treehugger also lists some edible plants for your garden. Some of them probably won't work here in Phoenix, but I would like to try a few, such as globe artichokes, sunflowers, chard and rhubarb. I know someone that has had success with figs.
Here are turfgrass alternatives.
If we move to a large lot, I would like to again have roses, grass and citrus trees (more this time!) in the back yard but would like to really dedicate a section to growing food. I'm still working on my green thumb though. It's still kind of brown! The front yard, I think, would be desert-fabulous. I love flowering cacti and some of the beautiful desert bushes and vines.