The iPhone 4's operating system represents a significant improvement on earlier versions of Apple's smartphone operating system. It's also got a new name - iOS - signifying the importance of the iPad alongside the iPhone.
And what's more, iOS 4 is available to users of the iPhone 3GS, third-gen iPod touch and 3G too (albeit with limited features with the latter). iOS 4 will be available for the iPad later in the year.
We've delved right under the hood of the new iPhone to bring you 20 tips for all those iPhone 4s out there.

1. Lock the screen orientation
If you're lying in bed reading an iBook or a page in Safari it can be annoying when the iPhone's orientation keeps flicking between portrait and landscape. You can solve this by activating the new Portrait Lock. Double tap the Home button to reveal all the running apps, then swipe your finger to the right to reveal iPod controls and the Portrait Lock.




iPhone 4 tips

2. Tap to focus/zoom in Camera 

The iPhone 4's new 5 megapixel camera has a fantastic digital zoom. But to activate it you first need to focus on an object – like a face, for example, in your view. Do this by simply tapping anywhere on the screen. A white square will appear showing you the object that the iPhone is focused on. A zoom bar will also appear, which you can use to zoom into the object you've picked.
iPhone 4 tips

3. Multitasking: update your apps

Multitasking is one of the big new features of iOS4, but while all Apple's apps (like Calculator and iPod) are compatible, all third party apps will need to be upgraded to properly multitask. So, you'll need to head to the App Store app on your phone, then visit the Updates section to download a update for each app. This can take a while, but don't forget, the App Store app also multitasks (as it always has), so double tap the Home button to get back to it to save time after selecting each update. There's also a handy "Update all" button to tap.
iPhone 4 tips

4. Switch to UK English 

If you're getting annoyed that your iPhone thinks colour should be spelt without a 'u' it's because you've got English (US) selected. You can easily switch back to English (UK) for spell checking by tapping the globe button next to the space bar in any app that brings up the soft keyboard (like Mail or Notes). This toggles your iPhone between English (UK) and English (US).



iPhone 4 tips

5. Multitasking: kill a running app 

After you've been using your iPhone for a while double-tap the Home button to see how many apps you have running - it will be more than you think! Normally you just let the iPhone decide how many it can keep running at once, but you can take matters into your own hands by killing running apps here. Just tap and hold on a running app and a "-" button appears against all of them. Tap this to kill the app.
iPhone 4 tips

6. Add an accent on the e and a key

It's possible to quickly add a variety of accents to the letters "e" and "a" when typing on the iPhone's keyboard. Just tap and hold on either key to reveal more options, like "é", for example.

iPhone 4 tips

7. Turn caps lock on

If you want to change your typing to capital letters all the time, rather than just for the next letter, then double-tap on the Shift key on the iPhone's keyboard. It will now turn blue, indicating caps lock is on. Just tap it again to turn it off.

iPhone 4 tips

8. Camera: take a picture of yourself 

The iPhone 4 has a front and rear-facing camera. The rear-facing camera is the high quality 5 megapixel one, and the front facing camera (used mainly for FaceTime video chat) is lower VGA resolution. This means it's now easy to take a picture of yourself (something that was pretty difficult on the previous iPhone models). In the Camera app just tap the Switch button at the top right to change cameras from rear to front.
iPhone 4 tips

9. Camera: email a video of yourself talking
You can also use the forward facing camera for recording video, and the iPhone 4's second microphone means it works well capturing anything you say too. In the Camera app tap the switch icon (as in tip 8) then change to video mode using the slider and record a video of yourself talking. Now select it in the Camera roll then tap the Forward icon and select Email Video - job done!
iPhone 4 tips

10. Make and rename folders
Organising your apps is so much easier on iPhones running iOS4. Just tap and drag apps on top of each other and you create intelligently named folders. You can rename the folder names Apple chooses though - just tap and hold on an app to make them wiggle, then tap on the folder name and start typing.
iPhone 4 tips

11. Make a FaceTime call 

When they first get an iPhone 4 a lot of people start looking for the FaceTime app to make video calls. Actually, there's no FaceTime app! To make a video call you simply make a regular call, then tap the FaceTime button in the Phone application. At the moment FaceTime is only available between iPhone 4 users on Wi-Fi. We would expect more compatibility going forward, as the FaceTime technologies are being ratified as an open standard.

iPhone 4 tips

12. Hide Caller ID

It's possible to hide your Caller ID when making calls on your iPhone. In the Settings app tap on Phone, then tap on Show My Caller ID and turn it to OFF. (Incidentally, if you ever forget your phone number, you'll find it in here too).

iPhone 4 tips 


13. Restrict features 

If you've brought an iPhone for your kids to use you might want to restrict some options, like the iTunes store and the App Store, for instance. You can also restrict the ability to watch age-rated content. In the Settings app click on General then Restrictions to turn this feature on and choose what you'd like to restrict.

iPhone 4 tips

14. Delete a text from the text history 

The iPhone Messages app records a history of all your text messages, like an instant message conversation. You can selectively delete old texts though. In Messages tap the Edit button at the top of the screen and then tap the radio button next to the offending text and tap Delete.
iPhone 4 tips

15. Watch live TV on your iPhone 

Not an iOS 4 tip per se, but you can turn your iPhone into TV thanks to the mobile version of the great TVCatchup website. You need to register, but the service is completely free, and even works over 3G as well as Wi-Fi.
iPhone 4 tips

16. iMovie and photos 

Apple's iMovie for iPhone 4 app means you can edit movies on your phone. Obviously it lacks the depth of the full iMovie for the Mac, but considering it runs on a phone it's very impressive. You can also add photos to your movie projects with a Ken Burns effect. One useful tip is to create an album of all the photos you plan to add to the project because otherwise you have to search through your camera roll, and for every photo you insert you have to start back at the beginning of the roll.

iPhone 4 tips

17. Show PDFs 

iBooks for iPhone can display PDF files as well as ebooks (as in the image below). To upload a PDF to your iPhone you have to use iTunes. First drag and drop your PDF file into your iTunes library, then when you sync your iPhone look in the Books tab. Here you'll find options for uploading the PDF. Once you've done that look in the iBooks app and a new PDF tab will have appeared. Tap this.


iPhone 4 tips

18. Get better reception

Apple's statement that there's a fault with the way the iPhone displays signal strength, which will be fixed by a future software update, is all very well, but people are still losing signal when gripping the iPhone 4 in a way that covers the gap between the metal bands at the bottom left of the phone. iPhone Bumpers (£25, from Apple), or in fact any third party case that covers the outside edge of the phone will solve the problem, since they prevent your skin from contacting the metal antenna.
iPhone 4 tips
19. Turn on SMS character count

A nice little update in the iOS 4 software is the ability to turn on a character count in the Messages app. You'll find the option in Settings/Messages. Now you'll be able to keep your overly long text messages in check!

iPhone 4 tips

20. Search more with Spotlight

The Spotlight search has been enhanced significantly in iOS 4. Swipe right from the Home screen to activate it. You'll notice that it now searches more things, including text messages in the Messages app. But if you keep scrolling down the list of results you'll notice two new options at the bottom of the screen – Search Web and Search Wikipedia. These are handy links that open up Safari automatically and start searching for you.

iPhone 4 tips