3 - clicking once on the arrow in the upper corner will display context sensitive help. Pressing the H key or the Help key will give the same results.
- HIDE GAME QUICKLY (in case your boss is coming)
Press the ESCAPE key.
This will hide the board and give a normal looking menu bar.
To unhide the board press the Escape key again or select Resume under the File menu.
Note: If you have made another program the active program then you will have to select the game again from the application menu, then do the above to unhide it.