Did you know that Mac OS X has a built-in zoom feature? This feature lets you zoom in on your screen so everything on the screen is larger. Of course, when you zoom in you can only see part of the screen on your monitor. You need to scroll around to see the other parts of the screen.

I use the zoom feature frequently when I’m giving presentations especially when I provide Mac training. I project my Mac laptop’s image onto a wall or screen using a projector. Then, I want to show audience members something on the screen so I zoom the screen so I can ensure that everybody in the audience can see what I’m trying to highlight on one part of the screen.

Zoom is off be default. Follow these instructions to turn it on.

• Go to the Apple menu and select System Preferences.
• Click on the Universal Access icon
• Click on the Seeing button.
• In the Zoom section set the button to On.
• Optionally, click the Options button and make sure in the section titled “When zoomed in, the screen image moves:” that it is set to “Only when the pointer reaches an edge”. Click Done. The other options lead to too much screen movement which I find distracting or even annoying.

Once the zoom feature is enabled then you can invoke it at any time to zoom in on your Mac’s screen by simultaneously pressing these 3 keys: Command, Option and the Plus Sign (which is typically the same as the Equal Sign key). Each time you press these three keys your Mac will zoom in a little bit more.

To zoom out simultaneously press these 3 keys: Command, Option and the Minus Sign key which is typically to the left of the Plus Sign key.

Did you know that you can take pictures of what’s on your iPhone’s screen? For example, you can take pictures of a text message, a web page or an email configuration screen.

The procedure is simple. Press and hold the Home button while simultaneously pressing and releasing the Sleep/Wake button.

The Home button is located near the bottom of the front face of the iPhone. This is the button that you typically press to exit an application and return to your Home screen.

The Sleep/Wake button is the button on the top edge of the iPhone which you typically use to put the iPhone to sleep.

Be aware that if you were to press and hold both the Home and Sleep/Wake buttons continuously for 10 seconds then this will reset your iPhone. Resetting an iPhone isn’t necessary very often but if your iPhone locks up and becomes completely unresponsive then resetting is often helpful. Resetting the iPhone essentially just forces the iPhone to turn itself off and then start up again. It does not remove any of the data or applications on the iPhone.

The ability to take a screen snapshot was added in version 2.0 of the iPhone software which was released in the middle of 2008. If you happen to have an original iPhone and have never updated its software then you don’t have the ability to take a screen snapshot with your iPhone.

Screen snapshots are pictures of a portion of the screen. Being able to take a screen snapshot can be very useful. I typically use this feature several times each day. Here are some reasons why I commonly take a screen snapshot:

• To capture the exact text of an error message that appears on my screen.
• To be able to print something that is not easily printed.
• To capture a part of the screen so I can send it as an email attachment, often in a set of step-by-step instructions. A picture is worth a thousand words.

I’m going to highlight the two most common ways that I take a screen snapshot. For a complete list of ways read this page. Simultaneously, hold down the Command key (aka Apple key), Shift key and the 4 key. The cursor will change from the arrow to an icon of a crosshair. Position the crosshair in the upper left corner of what you want to capture. Then click and drag to the lower right corner. Release when the entire desired area of the screen is selected. When you release the snapshot will be taken and automatically saved to the Desktop. In Mac OS X version 10.6 the file will be named “Snapshot” followed by a date and time stamp. In older versions of Mac OS X the file will be named Picture 1. Subsequent snapshots will be named Picture 2, Picture 3 and so forth.

You can rename the snapshots. You can double-click it to open it and print it. You can move yours snapshots into folders to keep them organized.

Sometimes, I don’t want to save a copy of the snapshot as a file on my Mac. Instead, I just want to capture something on my screen and immediately paste it into an email or some other document. In this case, I simultaneously hold down the Control key as well as Command, Shift and 4. I then position the crosshair the same way to capture the snapshot. However, in this situation the snapshot is saved to the Mac’s invisible “clipboard”. Now, I can go to an email message or a Word file and use the Paste command to paste the snapshot.