I just got one of those a week ago...
What to say.. it's a keyboard. it's small. it works. Wireless RF.
Trackball drives the mouse pointer. Quite accurate. Yes - left-right mouse buttons are next to the trackball. They are pretty hard to press - this is my only complaint about this device. They should've made the ball clickable (simulate left click) too. No backlight either. All in all - nice and not expensive (was on sale @ lenovo last week)