In Mountain Lion You Can:
Open the Preferences for any Apple program using ⌘, (thats the command key and the comma).
Get to the Menus two ways. The menus in the various menu bars offer two options. If you click on a specific menu, such as Edit, and continue to hold down the mouse, the menu will only stay open as long as as the mouse is held down. However, if you click on the menu name once quickly, the menu will stay open until you either make a selection or click in a blank space on your desktop.
Still close Sidebar Headings, but the method is different. Hold your cursor over the name of the Sidebar Heading and an option to to hide or expand appears. Just click on the option you need.
Control Scroll Bars. In Mountain Lion Scroll Bars are not prevalent because you can have the same function by scrolling with your mouse scroll wheel or with your trackpad. You can force the scroll bars to show all the time if you prefer that method. Apple Menu > System Preferences > General. Click on “always” next to Show Scroll Bars.