So I just bought the t650 today and with the help of
xev I was able to figure out how to get all of the button presses. I have not tried to map any buttons to specific functions but as far as I can tell here are the default mappings. As of yet I have not found a solution to tapping registering as a click. :-(
Button 1 (Left-click): This occurs whenever the touchpad is pressed down with 1 or 2 fingers so that either the front right and/or front left foot is pressed. Sole exception is when a single finger is pressed above the right foot.
Button 2 (Right-click): This occurs whenever the touchpad has a finger placed above the right foot and either front foot is depressed.
Button 3 (Middle-click): This occurs like a left-click event but 3 fingers are used to press the touchpad.
Button 4 & 5 (scroll-wheel): Button 4 occurs when two fingers are slid upward on the touchpad and button 5 when two fingers are slid downward.
Button 6 & 7 : Button 6 occurs when two fingers are slid to the left on the touchpad and button 7 when two fingers are slid to the right.
Button 8 & 9 : Button 8 occurs when three fingers are slid to the left and button 9 occurs when three fingers are slid to the right.
Of course moving one finger over the touchpad moves the mouse on-screen. I also found that moving three fingers up on the touchpad is the same as pressing the super (windows) key.
So that's what I found and I hope it is helpful to anyone who uses the t650.