It might not matter to you, but do you have an opinion or desire to go someplace? I would highly recommend the Western US (go to the national parks!
http://www.nps.gov/findapark/index.htm). And since you will be here in the Summer, I would stay towards the north. If I were you, I would go to NYC and take the train to Washington DC at the beginning or end of your trip. Then again, I have lived here my whole life and haven't been to New York City yet.
If you have a list of places you would like to live in, it also helps narrow down places where you can look for a temp job as a photographer. Don't just look in the city centers, but look at the suburbs around the cities as well. Also look at the weather/temperatures for that time of year. Florida or anywhere in the Southeast in July is hot and humid. From Texas to Arizona it is just hot. In the middle where I am, it is a little too flat and uninteresting.
My recommendation would be the Northeast (New York, Massachusetts, Connecticut), Colorado, Las Vegas, California(expensive), Washington state (Northwest). It's not to say that there aren't other places that are interesting or could work out for you. Maybe other people can give some suggestions or advice.
You can always make your own job here too if you have a good idea.