Last week, a new iPhone app called Tiger Text hit the App Store. The app lets users send text messages to a server that could be read by the recipient via an app reader. The text message would then be wiped from the face of the earth (i.e. both the texter and recipient's iPhones, and the server) after a pre-determined amount of time.The purpose of this app, of course, is to hide your tiger tracks. Makers of the app swear they came up with the app's name, Tiger Text, well before steamy Tiger Woods texts and voicemail messages that he'd sent to mistresses made headline news.[ Apple's bikini ban was too reactionary, reports CIO.com. | What's the App Store's dirty little secret? ]Tiger Text is supposed to give texters power over historical records of their private texts that they might hammer out one night and regret the next day\u2014but it's a false sense of control. Clearly, the makers of Tiger Text are betting that most iPhone owners who receive Tiger Texts messages don't know how to take a screenshot of the message. And maybe they don't.All of this got us thinking that a review of some of the hidden iPhone features is in order. The simplicity of the iPhone and lack of buttons belies a wealth of shortcuts. We've picked six of the most important ones.Two-Button ScreenshotWhat to do: In order to take a picture of whatever is on the iPhone screen at the moment, simply press the home button and the on\/off button together. The screenshot is added to your camera roll. Also, in Safari, you can copy an image on a website by pressing on the image and holding until the "save image" pops up. The image will be saved on the camera roll. (Note: This doesn't work in some native iPhone apps like AP Mobile.)Why it's important: Text messages, emails, websites, images often get inadvertently deleted. The screenshot shortcut is a fast way to save data.Double-Click CameraWhat to do: You can set your iPhone so that double tapping the home button brings up an application, such as the iPod or camera. Go to settings, general and home. Then select from home, search, phone favorites, camera and iPod. We recommend you set it on camera.On a related note, if the iPod is playing, double-clicking the home button from another app or while at home screen will call up limited iPod controls, not the camera. When the iPhone is locked, double clicking the home button will also bring up the iPod controls.Why it's important: Photo opportunities arise when you least expect them. That's why the ability to quickly bring your camera online is critical. The double-tap of the home button is much faster than scrolling through your screens and looking for the camera app. (Remember to unlock the iPhone first before double-tapping the home button or else the iPod controls will pop up.)Three-finger Zoom\nWhat to do: With three fingers, tap the screen twice and you'll zoom in. It doesn't matter if you're on the home screen or in an app. Perform the action again to return to normal view.\nWhy it's important: This feature can make it easier on the eyes. On the home screen, app icons and the words beneath them appear bigger. But the real advantage comes in the camera. If you called up your camera app using the double-click feature described above (as opposed to scrolling and calling up a feature-rich camera app like Snapture), then chances are the photo opportunity is fleeting. A three-finger double tap can zoom in on the subject.Hold for Voice ActivationWhat to do: Hold the home button down until voice control activates. Then you can issue voice commands such as calling someone or playing a certain song.Why it's important: Searching for contacts and numbers while driving is a recipe for disaster, not to mention maybe illegal. Voice commands keep you safer on the road.Double-Tap SafariWhat to do: When surfing the Web on Safari, it's hard to read text and view images on the tiny screen. If you're using two fingers to expand the content, our hunch is that you've probably just bought your iPhone. Instead, double tap the text or pictures to fit the screen. Double tap again to return to normal.Why it's important: Web surfing and content consumption is a lot easier and less frustrating than constantly having to pinch and reverse pinch. Your fingers will thank you, too.Voice and DataWhat to do: You've seen it in the Apple and AT&T ads. When on a voice call, you can put the call in speaker mode and then hit the home button to access other apps. It's one of the key selling points\u2014voice and data at the same time\u2014of the iPhone.Why it's important: At first, it might seem odd to multi-task during a call. After a while, you'll wonder how you ever lived without it.Tom Kaneshige is a senior writer for CIO.com in Silicon Valley. Send him an email at email@example.com. Or follow him on Twitter @kaneshige. Follow everything from CIO.com on Twitter @CIOonline.