This week we turn our attention to the screen on the left and the items it holds--Dashboard.

"Wait, screen on the left? What are you talking about?" I hear you silently demanding.

In the early days of Mac 101, I explained the purpose of the Mission Control application. By way of refresher, with Mission Control you can create separate desktop environments (or spaces)--one that displays open Mail, Contacts, and Calendar applications; another for Safari; and yet another for iPhoto and iMovie. By default, Dashboard occupies the first Mission Control space.

There are various ways to expose the Dashboard screen. If you have a Mac with a trackpad, just swipe three fingers to the right to expose it (or to the left if you've switched off natural scrolling in the Trackpad system preference). Alternatively, you can press the F12 key (in conjunction with the fn key, if your keyboard has such a thing); double-click the Dashboard application in the Applications folder at the root level of your hard drive; or press Command-Space to expose the Spotlight search field, enter Dashboard, and press Return.

Wuzzup with widgets

Now that I've told you how to find the Dashboard screen, perhaps I should mention its purpose.

There are times when you want to swiftly check a bit of information or perform a relatively minor task. For example, you might wish to look at the current price of your soon-to-be-least-productive stock, or check the weather, or run a quick calculation. You could launch an application or your Web browser to do these things, but wouldn't it be easier if you could flip to a screen and find just the tool you need for the job?

Of course it would, and that's the point of Dashboard. It's a place where Apple stores small applications called widgets that you use for these kinds of everyday tasks.

The Dashboard screen

By default, the Dashboard screen includes four widgets: Calculator, Weather, Calendar, and Clock. You can click and drag these widgets to any location you like.

Many widgets have a hidden talent. For example, if you click the portion of the Calendar widget that displays today's date, a sidebar appears that lists upcoming events. Hover your cursor over the Clock widget, click the small i (for Info) that appears in the bottom-right corner, and you can choose a region and city for the clock to display. (Click Done to flip the widget back around.) Perform this same hover maneuver over the Weather widget, click the i button, and you can track a different city's weather, choose to display temperatures in Fahrenheit or Celsius scale, and opt to show low temperatures as well as highs in the six-day forecast. When you click on the Calculator widget, you can perform calculations not only with its on-screen buttons, but also with the number keys on your Mac's keyboard.

These may look strangely familiar to some of you. And they should. Many of the default apps found on iOS devices look and perform similarly.

Adding and removing widgets

Helpful though the default set of widgets is, it's a fairly meager collection. Thankfully you can add more. To do so, first click the Plus (+) button in the Dashboard screen's bottom-left corner to switch to the Add Widgets screen. When you do this, a larger collection of widgets appears, including Ski Report, Contacts, Dictionary, ESPN, Flight Tracker, Movies, Stickies, Stocks, Tile Game, Translation, Unit Converter, and Web Clip (a kind of widget that I'll explore more fully later in the lesson). To add a widget to the Dashboard screen just click it.

Many of these widgets, like the default set, are configurable. Hover your cursor over them and look for the small i in the bottom-right corner. For example, when you click the Info button in the Stocks widget, you can add the symbols of Dow Jones and NASDAQ stocks that you'd like to track, simply by entering a company name in the Search field and clicking the Plus (+) button. Any stocks that match that name will appear in a menu. Click the one you want, and it will be added to the widget.

If you'd like to remove a widget you have two ways to go about it. The first is to click the minus () button on the bottom-left of the screen. Do this and X's appear in the top-left corner of each widget. Click the X on each widget you wish to remove from the screen. This procedure does not remove the unwanted widgets from your Mac completely. They're still available when you click the Plus button I mentioned earlier.

The other method is to hold down the Option key and hover your cursor over the widget you'd like to delete. The X will appear over just that widget. Click the X, and the widget is gone.

Adding third-party widgets

Sharp-eyed readers who've clicked the Plus button to add a widget have spied the More Widgets button at the bottom of the Dashboard screen. When you click this button, Safari launches and takes you to Apple's Dashboard Widgets page. Here you'll find categories of available widgets. Select a category, choose the widget you'd like to add, and then click the Download button that appears below the widget. You'll be asked if you'd like to install the widget in Dashboard. You wouldn't have gone to all this trouble if you didn't want the thing, so click Install. The widget will be added to the list of available widgets on the Add Widgets screen. Just click it to place it on the Dashboard screen.

A couple of important warnings in this regard. First, Apple has paid very little attention to Dashboard widgets in the last little while. So some of the widgets available through this site may not work (or may not be available when you click the Download link because the host site has gone out of business). In some cases widgets don't work because they require Adobe's Flash media player, which isn't bundled with Mountain Lion. Others are just really old and don't work with the latest version of the Mac OS.

Because some widgets are so old, you may see a warning indicating that the widget is from an unknown developer and informing you that you can't download it. This is all part of Mountain Lion's Gatekeeper security scheme. When you install Mountain Lion, by default you can download and open applications obtained via the Mac App Store and from developers who have registered with Apple. If you attempt to open an application or widget obtained from a developer that's not registered with Apple, you receive this "Nuh-uh" warning.

If you're desperate to have one of these forbidden widgets, open the Downloads folder (found in your users folder and in the Dock), hold down the Control key, and click the widget you've downloaded. Choose the Open command from the resulting menu. A dialog box will appear that includes an Open button. Click that button, enter your account's user name and password, and click Install.

To completely remove third-party widgets from the Add Widgets screen, hold down the Option key and the icons will wiggle. Click the X that appears in the top-left corner of a third-party widget to delete it. (You can't delete Apple's built-in widgets.)

About Web clips

Dashboard offers an additional intriguing feature: The ability to create widgets based on website content. These special widgets are called Web clips and they work this way.

Launch Safari and navigate to a webpage that you visit frequently. For example, you might check a favorite news or social networking site each day. Choose File > Open in Dashboard. A purple bar will appear beneath Safari's toolbar, and the page will dim. Move your cursor over the column or element that you want to capture as a Web clip and click. A rectangle with positioning handles will appear. Drag those handles to resize your selection.

Now click the Add button in the purple bar above. The Dashboard screen will appear and display your selection as a Web clip. Any links within that clip are live, meaning that you can click them to launch Safari and move to the linked page. In addition, when the content on the host webpage changes, so will the content of your Web clip.

You can't resize the Web clip. If it's large, it's likely to take up much of Dashboard's screen. Also, if you delete it, it's gone rather than moved to the Add Widgets screen. If you want it back, you must re-create it using the steps I've just outlined.

You can customize the clip's frame and the size of its content area. To do that, hover your mouse over the clip and click the i button. When the clip flips around, you'll see that you can choose from six different frame styles. Pick the one that suits you and click Done.

If you find that adding a frame cuts off content that you want to see, click the i button again, click the Edit button in the resulting window; when the clip flips back around, click and drag in the middle of the clip to change its content's position, and click and drag the bottom-right corner to expand or contract the size of the clip's content area. When you're content with your work, click Done.

And that's Dashboard, an often overlooked feature of OS X that gives you quick access to tidbits of information and helpful tools.

Next week: We go on Safari