Microsoft Trackball Optical Mouse, Trackball (D67-00005)

the funny thing is i've never used a trackball before in my life.  but my mouse started going screwy (left button single clicks would act like a double click) and the only thing i had around was the microsoft trackball optical around that my friend didn't want.  so i was forced to use it.  now i can see the allure of a trackball even though my memory muscles still ache for a mouse.  i can see that if i use this for some time, i'll really like it even more.  but i wouldn't hesitate in recommending it.  the design of this trackball is very classy.  it just exudes quality construction.  MS can be criticized for a lot of things but they design solid products.  as far as cleaning it, that other reviewer is wrong.  there's a hole on the bottom of the trackball.  just poke your finger in there and out pops the ball.  i don't know how a person can not know how to pop out a ball.
note:  this is a trackball for the thumb.  there are other design types of trackballs where you control with your other fingertips.  i like the thumb design because your fingers are constantly at the mouse buttons and it makes drag and drop operations much easier.  the other designs, you constantly are shifting your hand position so it's easier to get tired than this design.