Three quick ways to view Notification Center
You can open Notification Center by clicking its menu bar icon. But here are other ways to display it:
1 Swipe. Use two fingers to swipe from the right edge of your trackpad to the left. (This works fine on a laptop, but less well with a Magic Trackpad, as your fingers can’t slide from the surface next to the trackpad.)
2 Use a hot corner. Go to either the Desktop & Screensaver pane or the Mission Control pane in System Preferences, and click the Hot Corners button. Choose Notification Center from the drop-down menu for the corner you want to use.
You can now open Notification Center by moving your cursor there; you close it by clicking elsewhere on screen or moving your cursor back to the corner.
3 Set a keyboard shortcut. In the Keyboard preference pane, click the Keyboard Shortcuts tab, and then click Mission Control. Notification Center is listed in that section; select its checkbox to add a shortcut, and type the shortcut in the field that appears. Pressing that shortcut toggles the display of Notification Center on and off.
Temporarily hide alerts and notifications
If you’re overwhelmed with notifications, you can pause Notification Center with one click – press Option while clicking the Notification Center icon at the right end of the menu bar. This pauses the display of notifications until the next day.
Alternatively, if you scroll down when Notification Center is visible, you’ll see a Show Alerts And Banners switch that you can toggle off. To reactivate Notification Center, Option-click the same icon again or toggle the Show Alerts And Banners switch on.
Pinch to zoom in Quick Look
In Mountain Lion, you can use two-finger pinch and spread gestures to change the way the files you’re previewing are displayed.
When you use Quick Look to view PDFs and web archives, spreading two fingers apart zooms in; pinching them together zooms out. (Oddly, these gestures don’t work with graphics files.)
With other file types, those gestures behave as they did in OS X Lion: Spreading switches you to full-screen view, and pinching returns you to a regular window.
To switch to full-screen mode when using Quick Look with a PDF or web archive in Mountain Lion, move the cursor to the title bar and spread your fingers. However, you can’t pinch to exit full-screen mode with these types of files.
Restore RSS Visualizer Screensaver Mountain Lion no longer includes the RSS Visualizer screensaver, but you can copy it from a Mac running Lion. On that other Mac, go to /System/Library/ Screen Savers and find the file RSS Visualizer.qtz.
Copy it to yourusername/Library/Screen Savers on the Mac running Mountain Lion. (Create that folder if necessary.) You can now select this screensaver from the Desktop & Screen Saver pane in System Preferences.
Keep your Mac awake
With Mountain Lion, you may find that your Mac goes to sleep when you don’t want it to (when you’re delivering a presentation, perhaps, or watching a video).
Say you’ve configured your Energy Saver preferences to put your Mac to sleep after 15 minutes of inactivity. You may notice that even when there’s an active process, such as a download, your Mac still goes to sleep after 15 minutes. Some users have even reported this happening when they change the sleep setting to ‘Never’.
There is a solution to sleepy Macs, in the form of a new command, caffeinate. To implement it, type the following command in Terminal: caffeinate -u -t 3600.
The 3600 there indicates the number of seconds before the system’s sleep settings go into effect; in this case, the 15-minute countdown to sleep won’t begin until 3600 seconds have passed. You can also run the command without the time switch; in that case, your Mac will stay awake until you stop the command by pressing Control-C in Terminal.
Select AirPlay device from menu bar
The standard way to play your Mac’s audio over an AirPlay device (such as an Apple TV or an AirPort Express) is to open System Preferences, click on the Sound pane’s Output tab, and select the device.
There’s a quicker way: If you have the Volume menu visible in the menu bar, hold down the Option key while you click on its icon. That will enable you to select audio inputs and outputs – including nearby AirPlay devices.
Unfortunately, this menu displays only the last selected AirPlay device. If you don’t want to use that one, you’ll still need to revisit the Sound preference pane.
Use multiple drives with Time Machine
Mountain Lion lets you specify more than one hard disk for Time Machine backups. Go to the Time Machine pane in System Preferences and click on Select Disk.
If you already specified a backup disk set and then you select a second one, you’ll see a dialogue box asking if you want to replace the current disk or use both disks for backups.
You are then told that if you use both disks, Time Machine will take turns backing up to each disk. This last option is especially useful if you have a laptop and want to back up your files to one hard disk at home and another at work.
If you want to tweet something by clicking a Share button or by using the Tweet field in Notification Center, there’s a quick way to send it: Instead of clicking on Send, just press c-Shift-D. You can also use this shortcut to send an email that you’ve composed.
BONUS TIP: Find apps fast with Launchpad
When Apple introduced LaunchPad in OS X Lion, it seemed suited only for Mac beginners. But with Mountain Lion, Launchpad has become much more capable as an application launcher.
To activate LaunchPad, you can either launch it from the Dock or the Applications folder; move the cursor to a hot corner you’ve specified in either the Desktop & Screensaver or Mission Control system preference; or press a keyboard combination configured in your Keyboard preferences.
You’ll then see a search field at the top of the window. You can use this field to quickly find any application: just type the first few letters of its name.
Launchpad searches by the name’s initial letters: pre will find Preview (as well as System Preferences), but rev won’t. Also, the search feature gives special weight to capital letters in an app’s name, so qt returns QuickTime Player, sp returns System Preferences, and p returns iPhoto, for example.