Do a short sale with a Realtor specializing in short sales. It's a lot of work for the Realtor and they need a lot of skills and knowledge.
Regardless, I'm sorry to hear about your situation. Almost 1/3 of all homeowners in the nation (and more than that in AZ) are faced with your same situation. I'm also sorry to hear you did not have any luck with a loan modification (but not surprised). Many of these so-called "experts" are doing what homeowners can just as easily do on their own. I hope you did not waste too much money on their services.
A short sale does sound like your best option. Visit our website. We are CDPE (Certified Distressed Property Experts), and the bulk of our business is helping homeowners like you avoid foreclosure through a short sale. Also, feel free to contact me directly if you have any questions. Either way, good luck!
Summit Home Consultants