To take a screenshot on your iPhone do this:
Hold the Power button while you press the Home button. The screen flashes and the screenshot is now saved in the Photos App.
If your iPhone is frozen you will need to force restart it. You can do this by holding the Power button and the Home button down until the screen goes black and the silver apple logo appears.
Need to put a period at the end of the line...You don’t have to switch to the punctuation section on the keyboard to add the period. Double tapping on the space bar will add a period and a space afterwards.
Want to rearrange the icons on your iPhone screen? Hold down on any icon on the iPhone's screen. The icons will start to wiggle. Now drag and rearrange the icons the way you like them. To stop the icons from wiggling press the Home button.
Need to place the cursor between two letters on an email or web address on the iPhone? Here's an easier way to do it than just tapping and hoping you land in the correct position. Hold your finger down over the word and you'll see a magnifying loupe magically appear. There is also a small vertical line designating where the cursor is located. Now it's easier to slide your finger to the correct position.

Too Many Pages error in Safari on iPhone. This is an annoying message that pops up when you are surfing the web on your iPhone.

Here's how to resolve the issue. Firstly press OK to dismiss the error message. Now tap the bottom right icon, the rectangle
with 8 in it. This will bring up the open pages that have been loaded in Safari. You can only have 8 pages open at one time so that's why the error message appears. See the white X in the red circle in the picture below? Tap on it to close that page and continue to close the pages you wish.

Want to reload a widget in Dashboard?
For instance you want to make sure the weather widget has the right info. When you are in Dashboard hold the command (apple) key and press the R. Watch with amazement as your widget spins. More of a geek trick but…
If you get the spinning beach ball of death you might try this. Click and hold down on the troubled program’s icon in the dock. It may take a bit of time (20-30 seconds) but you should see a menu pop up and then be able to choose Force Quit from the menu. We find this works better than the other methods of Force Quitting a program.
Can’t find one of your frequently used Applications or Documents or Servers? Click on the Apple on the top left of the screen, move down to Recent Items and choose from lists of recent Applications, Documents and Servers.
Another variation on the tip above- Application's Icon missing from the Dock? Try this work around. Press the Command/Apple key + Space Bar. This opens up Spotlight, look at the top right of the screen and you should see spotlights search field just waiting for you to type in what you are looking for. Say you want the Address Book. After pressing Command/Apple + Space bar begin typing address book (or whatever the name of the application you want is called), you should see spotlight listing all things with address book in the name. The 'top hit' will be the application Address Book and it will be highlighted in blue. Now press the Return key on the keyboard. Presto, the Address Book is now open.
Keeping an Application in the Dock All applications are in the dock while they are open. But once you quit them they disappear from the Dock. To make them stay in the Dock after you quit them do this. Click and hold down of the application's Icon in the Dock. A menu will pop up and one of the offering will be to Keep In Dock. Once you choose this Keep in Dock you can quit the Application and its Icon will stay in the Dock.

Have a laptop? Miss having a forward delete key? If you press the fn key (fn=function) on the bottom left of the keyboard then press Delete you get forward delete.
Open Mail and can't find the Send, Reply or Get Mail Icon across the top of the window? It's probably because the clear oval gumdrop at the far right of the Mail's window. Press the evil gumdrop once and see if the toolbar with the missing icons reappears.
Want a quick way to enter a Web address into Safari or Firefox? Press Command + L to highlight the Address Field. Now just type in the web address you want to visit and press Return.
Need to Select Multiple Items? For instance do you want to select a bunch of junk emails to trash? Or maybe select 5 or 6 pictures in iPhoto to send by email? Here are two methods. If the items you want to select are all next to each other try this: click on the first mail or photo and let go. You should see it highlight to signify it’s been selected. Now locate the last item you want to include in the group, press the shift key and click on it. You should now see all the items, from the first click to the last shift, click selected. Now you can trash a bunch of email or send several photos all at once. What if the mail or photos aren’t next to each other? Then you need to employ the Command key (used to have an Apple on older machines) on the keyboard. Do this: click on the first item to select and let go. Now hold the Command/Apple key down and click on more emails or photos. All the ones you click on will be selected. Now you can trash, move or email the selected items.
Lost your wireless connection? Make sure your Airport is connected and connected to your network. Go up to the Airport symbol on the top right of the screen and click on it. You should see a list of available networks to join. The network name with the checkmark next to it is the one you are currently connected to. Obviously your network names will be different. In this picture all the networks listed are available to join without a password except one. If you look to the right of the iTero network name you’ll see a lock icon. That network is password protected and you’ll need to know the code to join it.
Want to switch between open programs or just see what’s open on your computer? Hold the Command Key on the keyboard down and press Tab. If you keep you finger on the Command key and let go of Tab you’ll see Icons of the open applications in the middle of screen. Now with the Command key still down press and release the Tab key. See how a white frame moves from one Icon to the next? When you have the white frame around an application you want to come to the front of the screen let go of the Command Key. This is a great way to switch between open programs. It’s really helpful to switch between two programs you are using all day long. Give it a try. It’s called the Heads Up Display.
Surfing the Web and need to enter in a new web address? The easiest way is to use this keyboard shortcut. Press the Command key and L. This highlights the Address field in most web browsers (think Location). Now begin typing in the new web address.
Want to quickly get to the Google Search field in Safari or Firefox? In Safari press the Option + Command + F to get into the Google Search field. In Firefox you can get to the search field directly by using the Command + K shortcut.