Rubik's cubes floating around in a colorful computer mouse. There are two liquids with different densities and the two cubes have medium density so they float around between the two layers of liquids (best seen in the second picture, with the mouse standing vertically in the box). I believe this mouse was created as promotional special item for the 2003 Rubik's World Championships. This is the only one I have left. More about "speedcubing" on my AboutMe page.
It's mint, I only took it out of the box to take the pictures and I've tested it with my laptop, it works perfectly. It has two large buttons and a scroll wheel and it works with USB (box says for Windows 98/2000/ME/XP and MAC) and PS2 (Windows 95/98/2000/NT/Me/XP). A short manual and driver software is included, but probably you don't need them, it should be "plug & play" (it was with my Win XP laptop and USB). One box corner is a little squeezed (see fourth picture), otherwise everything is in perfect condition. The cubes have the standard 6 colors, the extra white/green rows you see on the second picture are not the bottom side but reflections