This fantastic and amazing little bitty software bit lets you use one bluetooth mouse and keyboard (the mac version... I have not tried it with any other version) with more than one computer. And it's so good to your skin... well, I'm soaking in it! I mean, I'm using it right now, switching from my laptop keyboard with the failing 'e' to the bluetooth keyboard so I can actually type this without injuring my index finger slamming the e key again and again. And when I want to use the mouse and keyboard with the host computer? I just move the mouse across the screen to the edge where I "placed" it in the preferences, and it slides right to the next computer like the techno-magico it is. Best thing of all? I pay what I want for it. Donationware only. But this puppy is worth enough to me that I'd consider paying a lot. Maybe even enough to buy a beer. Or, you know, a gallon of gasoline. Now that's saying something.