Recently I had to do a bunch of manual annoying tasks in Preview. And one thing I noticed was that the process was taking a lot longer because I had to change the location that the document was saving from iCloud to my documents. About 5 in, I went ahead and combed through my global defaults real quick and found NSDocuemntSaveNewDocumentsToCloud, in NSGlobalDomain, which controls the default setting for the target location of an object to go to iCloud. To disable, which makes the default location of new documents on your local file system, use the defaults command and set that key to false: defaults write NSGlobalDomain NSDocumentSaveNewDocumentsToCloud -bool false Now, viola, sanity: Screen Shot 2013-02-05 at 11.21.57 AM iCloud is great. So in case you decide to change the setting back, the command to do so would be: defaults write NSGlobalDomain NSDocumentSaveNewDocumentsToCloud -bool true

Each user in Mac OS X can customize the location that their screenshots (aka screencaptures) will go. To do so you would edit the property list, customizing the location key. You can easily edit this file using the defaults command. For example, if we wanted to set the location to go to a folder called screenshots in the home directory of a user we could use the following command:
defaults write location ~/screenshots
You can also change the default type of screenshot which I cover here