I have wished on more than more occasion that I could get a mouse to work with my iPad. I would like to be able to move around the iPad with a mouse when I am using it in the keyboard dock, it would make things easier.
A hack has turned up that has been able to get the Apple Magic Mouse to work with the iPad via Bluetooth. The catch is that the iPad has to be jailbroken.
Once your iPad is jailbroken you can use the Magic Mouse by installing the BTstack Mouse app from Cydia. Apple should have let us use any Bluetooth keyboard and mouse with the iPad from the get go.