Urban and Mobile Gardening - Potatoes

We've been growing fruits and veggies in our backyard as much as we can since moving to Arizona. Ironically, we had citrus and herbs in LA, but that's about it. One thing we've never tried to plant is potatoes. But since getting together with some other urban gardeners, I've discovered some neat techniques for planting potatoes like verticle potatoe gardens that start out as just a 2 foot by 2 foot box of 2x4's filled with dirt, potatoes are placed in the dirt, and when the sprout grows above the top the dirt, another box of the same size is placed on top and dirt is added, and so it continues. Much like #6 in this post:  http://www.organicgardening.com/learn-and-grow/7-ways-plant-potatoes?page=0,5

This is the method I'd most like to try, and I think it could be made using scavenged wood pallets and the like. Tomorrow we are going back to the Fruit and Bread Barn, and we will see if the fingerling potatoes we spotted there the other day are still around. Unfortunately they were unable to take our debit card so this time we're going to bring cash.

P.S. Was up too late with the kittens (bottle feeding) and overslept this morning when Carlie and Patch took over feeding for a while, so didn't get to the store *sniff* BUT some friends stopped by and they're going to this place that sells compost and potting soil in large amounts for less money and some huge sturdy bags you can use as raised beds that are only 5 bucks each!!! I'm super excited!