If you've just purchased a spanking new Magic Mouse then you'll need this update to the software to get the most out of it.
Wireless Mouse Software Update is the official Apple Magic Mouse software and allows you to take advantage of the multi-touch features of your Magic Mouse. Without it, your mouse will be sorely lacking in full functionality. Note that you will need Snow Leopard Mac OS X v10.6.1 before installing this update although we've also provided Leopard users with a version too.
If you've just purchased your Magic Mouse, then Wireless Mouse Software Update is an essential download.