walk-in shower - great way to keep air circulation and not worry about cleaning a glass door or washing curtains. I HATE SHOWER DOORS. If we ever build a house, I'll do a walk-in grotto-style shower and never scrub another nasty door again!
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.