To get the Photo Stream working on my MacBook I found out that I had to BUY an upgrade for an application that I don't want: iPhoto.
Looking for a solution I found that iPhoto stores its pictures in a specific location and the Photo Stream is updated even if iPhoto is not running. The goal was to create a script that copies all of the images from many sub-directories into a single folder.
As there are many people who know a lot more about OSX I would welcome improvements and feedback. Some areas to look at:
tell application "Finder" set this_folder to "Macintosh HD:Users:duittenb:Library:Application Support:iLifeAssetManagement:assets" as alias set target_folder to "Macintosh HD:Users:user:Pictures:MyStream" as alias try duplicate (every file of the entire contents of this_folder whose name contains "IMG") to the target_folder with replacing end try end tell
Mac OS X Hints
http://hints.macworld.com/article.php?story=20120120073300575