DIY - Glow in the dark pots with mums for fall/Halloween. Buy a flower pot that you really like and use Rustoleum's Glow-in-the-dark paint to paint the pot. During the day, the paint will absorb the sunlight and at night the pots will glow.
Pondless Backyard Fountain Pond and Waterfall. Even without the fountain, which in Az will grow algae like nobody's business, I think the idea of softening up the patio with a little rock garden with plants mixed in.