Most Windows fans refer to the row of tiny status icons at the lower-right corner of the screen as the tray, even though Microsoft’s official term is the notification area. (Why use one syllable when eight will do?)
Macintosh folks wage a similar battle of terminology when it comes to the little menu-bar icons shown in Figure 1-5. Apple calls them Menu Extras, but Mac fans prefer to call them menulets.
In any case, these menu-bar icons are cousins of the Windows tray—each is both an indicator and a menu that provides direct access to certain settings. One menulet lets you adjust your Mac’s speaker volume, another shows you the remaining power in your laptop battery, and so on.
Making a menulet appear usually involves turning on a certain checkbox. These checkboxes lurk on the various panes of System Preferences (Chapter 17), which is the Mac equivalent of the Control Panel. (To open System Preferences, choose its name from the 
menu or click the gear icon on the Dock.)
Here’s a rundown of the most useful Apple menulets, complete with instructions on where to find the magic on/off checkbox for each.
AirPlay (
) lets you send the Mac’s screen image to a TV, provided that you have an Apple TV (details on The Finder Sidebar). This menulet turns blue when you’re projecting, and its menu lets you turn AirPlay on or off. To find the Show checkbox: Open System Preferences→Displays→Display tab.WiFi (
) lets you turn your WiFi (wireless networking) circuitry on or off, join existing wireless networks, and create your own private ones. To find the Show checkbox: Open System Preferences→Network. Click Wi-Fi.Battery (
) shows how much power remains in your laptop’s battery, how much time is left to charge it, whether it’s plugged in, and more. When you click the icon to open the menu, you see how many actual hours and minutes are left on the charge. You can also choose Show Percentage to add a percentage-remaining readout (43%) to the menu bar.This Battery menu also shows something that can be even more useful: a list of the most power-hungry open programs (“Apps Using Significant Energy”). That’s handy when you’re trying to eke out every last drop of battery life for your laptop. To find the Show checkbox: Open System Preferences→Energy Saver.
Tip
If you Option-click the Battery menulet, you get to see the status of your battery’s health. A Condition command appears. It might say, for example, “Condition: Normal,” “Service Battery,” “Replace Soon,” or “Replace Now.” Of course, we all know laptop batteries don’t last forever; they begin to hold less of a charge as they approach 500 or 1,000 recharges, depending on the model.
Is Apple looking out for you, or just trying to goose the sale of replacement batteries? You decide.
Bluetooth (
) connects to Bluetooth devices, “pairs” your Mac with a cellphone, lets you send or receive files wirelessly (without the hassle of setting up a wireless network), and so on. To find the Show checkbox: Open System Preferences→Bluetooth.UP TO SPEED: Where Your Free Hour of Battery Life Came From
Some of the features Apple works hardest on are things you’ll never even see.
One big category: technologies designed to save battery power. Since 75 percent of new Macs are laptops, battery life is a big, big deal.
Here are some of these behind-the-scenes juice-preservation techniques in recent OS X versions, bearing the names Apple has given them:
App Nap. When a program’s window is completely covered up by other windows, the Mac slows down that background app. (Ditto for Safari background tabs.)
Slower means less power-hungry—as much as 23 percent, Apple says. (If the app is doing something in the background, like downloading or playing music, then App Nap doesn’t kick in.) The instant you bring the program to the foreground, it snaps back to full speed.
Timer Coalescing. OS X attempts to consolidate processing tasks and feed them to your Intel chip in bursts. That way, the processor earns tiny micro-vacations—idle time. More idle time means less power use. Your savings this time: as much as 72 percent.
iTunes HD Playback Efficiency. By reducing the frequency of hard-drive access during iTunes video and audio playback, Apple says the Mac uses up to 35 percent less energy.
Safari Power Saver. Flash videos and animations are famous battery hogs. So when Safari spots a Flash video off at the edges of a Web page—on the side or the top, for example—it concludes that what you’ve got here is an ad. And it stops the ad from playing until you click on it. (You see a banner on the video that says “Safari Power Saver. Click to start Flash Plug-In.”)
Apple says all of its power-saving features together can extend a MacBook Pro’s battery charge by as much as an hour. Not bad for a free system-software upgrade, eh?
Tip
You can Option-click this menulet to see three additional lines of nerdy details about your Bluetooth setup: the Bluetooth software version you’re using, the name of your Mac (which is helpful when you’re trying to make it show up on another Bluetooth gadget), and its Bluetooth MAC [hardware] address.
Clock is the menu-bar clock that’s been sitting at the upper-right corner of your screen from Day One. Click it to open a menu where you can check today’s date, convert the menu-bar display to a tiny analog clock, and so on. To find the Show checkbox: Open System Preferences→Date & Time. On the Clock tab, turn on “Show date and time in menu bar.”
Time Machine (
) lets you start and stop Time Machine backups (see Chapter 5). To find the Show checkbox: Open System Preferences→Time Machine.User identifies the account holder (Chapter 15) who’s logged in at the moment. To make this menulet appear (in bold, at the far-right end of the menu bar), turn on fast user switching, which is described on Fast User Switching.
Volume (
), of course, adjusts your Mac’s speaker or headphone volume. To find the Show checkbox: Open System Preferences→Sound.
To remove a menulet, ⌘-drag it off your menu bar, or turn off the corresponding checkbox in System Preferences. You can also rearrange menulets by ⌘-dragging them horizontally.
These little guys are useful, good-looking, and respectful of your screen space. The world could use more inventions like menulets.