I got the Logitech mousin' software going, and my 4th button is a menu that pops up, giving me Start, Close, Minimize, scroll hori, scroll vert, next window, menu all within close reach. Here's what I do to close a window:
#1. Press button.
#2. Flick wrist to the upper right about 1 cm.
#3. Let go of button.
For minimize:
#1. Press button.
#2. Flick wrist up about 1 cm.
#3. Let go of button.
For start menu:
#1. Press button.
#2. Flick wrist to the lower left about 1 cm.
#3. Let go of button.
You guys get the point. Very useful. Beats any Microsoft mousing software. I do like that 5th button though....and the explorer mouse beats the intellimouse any day. no one ever uses their pinky to press the 5th button...it's better off next to the 4th button. just my 2 cents.