Apple is well known for including little messages in strange places and System 7 is no exception.
(73) In the Color Control Panel, option-click on the Sample Text a few times.
(74) In the Monitors Control Panel, click on the 7.0 in the upper right corner.
(75) Type MID into the new city box in the System 7 Map Control Panel, and select Find.
(76) In the Map Control Panel, click on the 7.0.
(77) Hold down command-option and choose About the Finder. If your Desktop folder (invisible) was created after the release date of System 7 (5/13/91), then be patient and you will get a surprise in the resulting dialog.
(78) Delete all the label descriptions in the Labels Control Panel, restart and look at the Label menu.
(79) In the Memory Control Panel, turn on Virtual Memory, hold down the option key and click on the name of the hard drive for a surprise.
(80) For another surprise open the data fork of the System file with Word (hold down the shift key and Open becomes Open Any File...). If you don't have Word use any disk/file editor like Norton Utilities or FEdit.
(81) The Color Map in the Scrapbook can replace the one in the Map Control Panel. The linked rings in the Scrapbook can replace the Apple in the Puzzle. Any PICT can be pasted into the Puzzle, including icons. Choosing Clear from the Edit menu gives you the old familiar numbers.