GodMark2
Master Poster
To just hide it:
Click on the little UP arrow, go to Customize.
Find the icon (GWX) in the list and change the setting to hide or show what you want. I put it to "Only Show Notifications" and the icon doesn't show in the taskbar now.
For Win7, it's the guillemet [»] button in the system tray area (where that icon shows up).