Well, I know it's possible, but are many people ACTUALLY represented outside of their area? I've already expressed my trouble finding a legit agent in Arizona, so I am thinking of trying some places in Southern California and New Mexico. I can travel for jobs, but I know that many places don't want the trouble of having someone who isn't local. Most agencies here get their work from New Mexico, so I thought I might have a good shot if I had a good reel. Any thoughts?

I am represented in New Mexico. I have a great agency. The Phoenix Agency. They are SAG affiliated and good at keeping contact with you. The are based in Albuquerque. However, they will only be able to get you work in NM, not outside of the state.
It doesn't hurt to have representation in other states for sure.

While I think that it is a great idea to get repped out of your area, it is sometimes difficult to convince an agent because if you live several hours away and a breakdown comes out, you will get very little notice about the audition. Also, would you want to be travel LONG distances all the time just for auditions. Suppose you never book anything? I think it would get old quickly. I think that if you want to work in a major marker (LA or NY) you need to be within commuting distance.

I also think it depends how far away from where most of the auds are. We live in Nj (out of ny) but it can sometimes take us 1 1/2 hrs (only 1 hr if no traffic) but becuase i have quite my job to help my son further his 'career' I just try to make that known to possible prospects. They like to know that on the drop of a dime you can get into an aud sometimes with just a couple hrs notice, thats why they like you somewhat near by. So (if your a minor) have someone willing to do that for you or if you arent a minor and can do it yourself make it known you can be 'on call' that could help.

There are also Voicemail services you can get real cheap with area codes for the area you want to be repped in. If you put that phone number on your resume, they'll be none the wiser you live outside the area. The only problem with that is, if there's an audition they want to send you on, you have to make last minute arrangements to get there, which if it involves a flight, can be extremely costly. The upside to it is that if you book the part, your expenses can be written off on your taxes!

Avidactor brings up a good point! You can get a voicemail or a cell phone number with the area code of where you want to be repped. If you already have a cell phone, which I am almost certain you would in this day, you could get a really inexpensive pay as you go or prepaid cell phone with a NYC or LA area code and just treat it as voicemail. Then if you get voicemail, call them back on your regular phone to save the prepaid minutes.