I JUST received one of those in the mail yesterday. I ordered it from some guy based in Texas on E-Bay. I wound up with the Translucent Blue 3" trackball and a mounting plate for it. I'm not even sure if I'll illuminate the trackball since the natural blue color of it looks really sweet.
It's an awesome trackball and requires no encoder. I just hooked up a couple of spare pushbuttons to it, then plugged it into my laptop via the USB cable. Worked just like a mouse and I had some fun playing Simpsons Bowling with it on my laptop.
The ONLY question I have with regards to the trackball is the presence of two green wires which are crimped together in a circular connecting device. The instructions that come with the trackball show the two green wires, but don't label them or say what they are. I believe they are ground wires that may need to be attached someplace, but I have no idea if that is right or not. In the attached picture, they are the green wires whose end is hidden by the joystick. What the heck are they? They aren't for the USB/PS2 connection, and they also aren't for the buttons.
One other oddity is that the quick disconnects for the buttons have a splice at the end of them. Is that designed to hook up two buttons at once? It's just a bit confusing and I'm wondering what their purpose is.