Yo Photo people:
I believe Vermont, Skowhegan and Lightwork are great places to apply. I have had friends and peers that have gone and highly recommend them. That being said, most residencies are not really grad school "prep", because they tend to look at exceptional bodies of work, a decent exhibition record or those that have completed an MFA. This is not always the case, but it is pretty competitive.
But, you never know unless you apply!
I just did a photo residency at Atlantic Center for the Arts this past fall with Rineke Dijkstra. ACA was brilliant. Last year, they had Thomas Struth. They rarely have photographers, but when they do---it's a magical place to live for a month (on the beach) and work alongside some of the most amazing artists. There were 7 of us and I was the only one without an MFA. I have no clue how I got so lucky...but, I'm glad I applied. The staff said depending on the popularity of the master artist you could be up against 35 other candidates or 200. Mine was pretty popular because of who Rineke is. But, some of them are easier to get into. And you can apply as many times as you want. (Each year...)
http://www.atlanticc...r_dijkstra.html
Only down side...you have bring your own equipment. Not as awesome as Lightwork where they have beautiful darkrooms. But, VSC is like that, too. So....
Incidentally, I got 100% grant funding from the Joan Mitchell Foundation. SCORE!
So, yeah...They are out there. You just have to look.