I also have recipes for my instagrams (and the instagrams of a few friends) to be put in a special folder in my Dropbox. Then (so I don't waste space on my Dropbox) I have a cron that periodically moves them into a local folder on my Mac. And I then occasionally load up that folder as the screen saver photos on my Apple TV. Unfortunately, I haven't figured out how to make that last step automatic.