How about a Mouse Mover application which can run on Mac or any other operating system which supports running a java application? The Software presented here can keep the mouse cursor moving on any operating system on which you can run a java based application (.jar file).
Download the Mouse Mover application and run it on Mac or any other OS which supports running of java application. This download requires atleast Java Version 1.6 installed on your computre. In case of Mac, you would need atleast Mac Leopard.
The above software download can even be used on any Windows based Operating System as well. The Software download presented here is similar to that described in the post Keep Mouse Moving which presented a windows based software. The download file presented in first paragraph is a .zip file containing a .jar file and other files in a folder. All you need to keep your computer active and let the mouse cusror move automatically is extract the contents of the zip file to a folder on your operating system (The OS must have Java Run Time installed already to run this Mouse Mover application) such as Mac, Windows, etc and launch the MouseMover.jar file.