It's an interesting program that could be a good alternative to the boring default Windows screensavers. It automatically includes a long list of major cities from around the world, so you can choose to view the moon from any one of them and switch the perspective whenever you like.
You can also add cities manually. Just enter the exact coordinates of the location you have in mind (Google can help you out with that part), and Actual Moon 3D will simulate the corresponding vantage point.
Lastly, Actual Moon 3D can optionally display some additional information, like the date and time of your chosen location, the rise and set times of the moon and sun, and more.