I haven't yet acheived the yard with no lawn, but I have 1/4 less lawn than when I bought my house three years ago. I've replaced the lawn with garden beds, walkways, and trees. Now I just need to research a bit further to find something that will do well in the desert, and yet not be too aggressive.
The longest journey starts with a single step. 1/4 less is a great start. Just the fact that you're moving in that direction deserves credit. You might want to find Scott Calhoun's website for more info on appropriate species. He's a brilliant designer in the Tucson area and has written a few great books.