Apple keyboards are USB 1.1. Will only support a mouse, and not a USB stick or drive. Anyway, the old ones are like that. You'll also find the mouse cable to be extremely small ... meant to fit from the keyboard and not the back of a machine. The keyboard has two ports, one for a left handed and one for a right handed person. On the older mice (before the "mighty mouse") there was only a left click, which made sense for both right and left handed people. Right click was achieved through a CTRL click, for the contextual menus. You didn't really need the contextual menus the way you need them in Windows. I still only use the left mouse button on my Mac.
Jay