Having a small daughter, walking the malls around here gets old. A friend and I recently took our girls to the zoo and had a great time. 99% of the zoo is stroller friendly. I think the only place I had to park it was the petting zoo and the monkey enclosure. Over all the zoo is beautiful and very well kept, even for it's age. I love that some of the exhibits really show off Arizona's beautiful landscape.
I highly recommend packing a lunch and eating in the picnic area though as food is abnormally high priced, even for a zoo/amusement park.
Also, if you think you'd use it, BUY A MEMBERSHIP! It's like $75 for two adults and two children and you don't always have to take a spouse, you can bring a guest! Kids under 2 are free anyhow but at $16 each for adults it's totally worth it after just a couple of visits.