I know that there were some 3rd party apps that could do this in the past, but with each new version of Mac OS X, it seems that many of those 3rd party apps stop working or the project ages and loses it's maintainer.
I'm wondering if there is a Mac OS X built-in keyboard shortcut to do this. I suppose this wouldn't be limited to finder windows, but for windows of any application.
Best Answer
As far as I know, there is no "out of the box" way or any system shortcut, to be able to align or arrange Finder windows. However, using Script Editor.app to create an AppleScript to set the bounds (size and location) of the finder windows, you can then bring your finished AppleScript code into Automator.app by creating a new document in Automator and selecting "Service" as the new document type.
The next step would be adding a run AppleScript action to the workflow, then paste the previously mentioned AppleScript, which we compiled in Script Editor.app, into the run AppleScript action in Automator
Next you would save and name the Automator service (I named it "Arrange Finder Windows"). After this, your new service will be available in system preferences at which point you can assign it a keyboard shortcut.
Now let's take a look at the process involved in creating the script in Script Editor.app, to manipulate the Finder windows. Using my 15" MacBook Pro, I have 5 different Display Resolutions I can choose from. What I'm getting at is, if my current display resolution is set at "Default", whatever code I create which will manipulate finder windows, Will function correctly only when I'm using the default display resolution. At a later point if I decide to change my Display either higher or lower, the code I created while using the default display, will actually place the Finder windows in different locations as they were originally meant.
In short, the goal here is to be able to align and arrange Finder windows(processing from one up to six windows) no matter which Display Resolution I am currently using.
This first part of the following code sets property values for all five different display resolutions I can choose in system preferences
This next snippet of code will retrieve the actual display resolution currently being used on the monitor
This next snippet determines which script object to run based on the current display resolution. (I created five different script objects, one script for every Display resolution... Each of which contains different values for the bounds of the finder windows
Here is the full script which will be placed into Automator
Be sure to set the property values to your monitor's available Display Resolutions, at the top of the script
To set the size and locations (Bounds) of the Finder windows, manually position and size (with your mouse) each finder window. Then in Script Editor, run this following code then simply copy the result coordinates and paste them back into the main script
Here is an example running the Automator service (which can be invoked by a keyboard shortcut) in Finder, starting with six windows, then all the way down to one window...