Aviassin Taskbar Eliminatorhttp://www.aviassin.com/taskbareliminator
From the help section:
Using Taskbar Eliminator:
For best results, it is advisable to first resize the Taskbar to the smallest possible size before running the program.
When you run Taskbar Eliminator for the first time, the taskbar is automatically hidden. To unhide it, simply press Alt + T . To hide the Taskbar just press Alt + T again (this shortcut toggles the Taskbar on or off).
To view the Taskbar Eliminator preferences window, press Control + Alt + T . This window allows you to set startup options, toggle the Taskbar, and exit the program. The Taskbar can be set to be hidden every time Windows starts.
For use with Dock applications(those with a system tray 'docklet' or plugin), Taskbar Eliminator also has a system tray icon. Right-click on this to show the preferences window or exit the program.