I have been a fan of Logitech products for a very, very long time (who remembers the Logitech Bus Mouse?). Not only because they are a Swiss company, but even more because they make good, innovative, quality products. My latest acquisitions look like they will fit nicely into those categories - innovative and quality products - the Unifying line of keyboards, trackballs and mice.
First, some background. I got these devices for use on the workstation at my job. Like many companies, I assume, my employers don't exactly put a lot of time, effort or money into the keyboard and mice that is supplied with a workstation. In general, they take whatever mediocre-to-poor peripherals come bundled with the system, and pass them along. Therein lies the first problem, it is almost always a wired keyboard and mouse, and I hate having wires running all over my desk. Even more important, the second problem, I much prefer a trackball to a mouse. Which then leads to the third problem, once I have replace the wired mouse with my own Logitech Cordless Optical Trackman, whenever one of my co-workers needs to show me something on my workstation they start dragging the trackball around my desk (which doesn't produce much useful effect), or they see that it is a trackball and they recoil as if they had found a pile of something on my desk that they didn't want to touch. So, I keep a "guest mouse" handly - which makes for a total of three input devices, and thus consumes three USB ports. Not good.
Some time ago Logitech started with their "Unifying" product line with some keyboards and mice which could use a single Nano-size USB receiver. But they didn't have a trackball, so I had been holding out, hoping that they would make a Unifying-compatible version of my Optical Trackman. Well, no such luck yet, but now they at least have an updated trackball, which meets my minimum requirements of having forward/backward buttons and a scroll wheel. So I decided to take the plunge.
The "magic" of pairing multiple devices to a single receiver is done by software provided by Logitech. Unfortunately, that software only runs on Windows (sigh), and you have to have administrator rights to install it. Ugh. Without it, each Unifying device will work with its own receiver, but then I am back to using three USB ports again. Fortunately, a bit of web searching led me to an explanation which made it clear that the "pairing magic" only had to be done once, and it stuck with the specific receiver and device after that, even if the USB receiver was moved to another system. So I got out my trusty HP 2133 Mini-Note, which can still boot Windows XP, loaded the Logitech Unifying software on that, and paired all three devices to one USB receiver. Then I moved that receiver back to my company workstation, and they all work just fine. Hooray!
One final test... I booted one of the Linux installations on the 2133 (Mint 10), took the Unifying USB receiver from my workstation and plugged into the 2133, and all three devices still work just fine. This is very good news!