Was I ever wrong!!
Here are 23 things I didn't know (and I know I'm just scratching the surface).
1) Battery. Avoid surprises: make the percentage of remaining battery life appear next to the battery icon on the upper right corner of the iPhone screen. To do this, tap Settings-->General-->Usage-->Turn on Battery Percentage. A numerical percentage helps you check the battery regularly, as opposed to suddenly being surprised by a red battery icon.
Don’t run on battery whenever possible. Plug the device in. Battery life is finite and is shortened every time you run completely out of charge.(Wish I'd known this one way sooner!)
2) Screen Shots. Tapping the home button and on/off button at the same time will take a screen shot that's stored in the camera roll. You can edit the screen shot within the camera roll and save the edited version.
3) Lock Portrait Orientation. Lock the screen in portrait orientation to read more easily on your phone. (Avoid the wobble between portrait and landscape this way.) To activate the lock, tap the home button twice, then scroll right, at which point you'll see a square gray icon with a circular arrow on the far left. Tap this to lock the screen (A message reading “portrait orientation locked” will appear at the bottom and you'll see a locked icon in the top right of the display now) and unlock by tapping again (message and icon disappear).
4) Create a Home Screen Icon for Any Website. If you regularly visit a website that doesn’t offer its own app, you can add a shortcut for that webpage to your home screen. Use Safari to load the page you want to bookmark. At the bottom of the screen, press the icon that shows an arrow leaping out of from a square. Then choose “Add to Home Screen”. Label it, press “Add” and a shortcut icon to the site will appear on your home screen.
5) Turn E-books Into Audio Books. Use the VoiceOver feature (which reads what’s on the phone’s screen) to read ebooks out loud. Go to "Settings," then "General," then "Accessibility" and toggle VoiceOver to "On," at which point you get options to tweak the settings (the speed of reading) and try out the new controls. Once activated, if you head over to your iBooks app, VoiceOver will read your selected texts to you.
Then open a book. Tap the first line (to get the highlighting off the buttons at top).
Now swipe down the page with two fingers to make the iPhone start reading the book to you, out loud, with a synthesized voice. It even turns the pages automatically and keeps going until you tap with two fingers to stop it. Note: I haven't tried this with Overdrive's e-books yet.
6) So Settings has a Caps Lock After All! In the Settings menu, go to General, then Keyboard, and then slide next to the entry Caps Lock to the left. Mine was actually enabled, but I didn’t know enough to double-tap the Shift key to get it to work, and tap it once again to disable. When locked, the Shift key turns blue.
7) Dismiss Keyboard Suggested Word. To dismiss the keyboard-suggested spelling of a word, you can tap on anywhere of the screen. You do not have to press “x” button at the end of the word.
8) Inserting a Period. When you are typing on your iPhone, simply double tap the “Space Bar” button at the end of a sentence. It will automatically insert a period followed by a space. It saves you a lot of time instead of pressing “123″ to get the numbers and symbols page where the period located in.
9) Hold Keys for Extras. If you hold down certain letters or punctuation keys, a pop-up appears containing other options. For example, you can hold down the dollar sign currency symbol to get other symbols for other currencies.
10) Cut, Copy, and Paste Text. Double tap on the text and wait for an options button to appear. Select the text to be copied or cut. Tap once where you would like to paste the text and tap Paste to do so. You can also ask for spelling suggestions and definitions from the options bar. If you don’t see these options, tap on the right arrow to reveal them.
11) Add Words to Your iPhone’s Dictionary. Open Settings, General, Keyboard, scroll down to shortcuts and tap Add New Shortcut. Type the word into the phrase box and leave the shortcut box empty. Tap Save.
12) Shortcut to Top of iPhone Screen. Tap on the status bar at the top of the iPhone screen to quickly scroll to top of page in web browser, email, or SMS message.
13) Use the Multitasking Bar to Move Quickly Among Apps. Press the home button twice to bring up the multitasking bar. All of your open apps will appeal so you can swap between two recently opened apps without having to close the one you are using.
Close the apps you’re not using so they don’t drain your battery. Access the multitasking bar to check for open apps, and close the apps by tapping and holding the icons, then tapping the minus. (Wish I'd known this one earlier too.)
14) Silence your iPhone. Woops! Forgot to turn off the ringer on my phone. Tap one of the volume buttons on the side of your phone to immediately silence your phone if it is ringing or vibrating.
15) Redial. Open the phone app and tap on the keypad icon. Then tap the Call button twice and the IPhone will redial the last dialed number.
16) Search for Anything on Your iPhone – Spotlight Search Access Spotlight search by swiping to it (left of the first screen) or pressing the home button while on the first screen of apps. Now you can search your entire iPhone for contacts, apps music, podcasts, video, audio-books, notes, emails, calendar entries, and SMS messages. Use Spotlight to quickly dial a contact or launch an app, or to search the web.
17) Too Many Icons? Create Folders.
Group up to twelve apps together in a folder by dragging one app on top of the other. This creates a folder that you can name and move around. You can also place your folder on the dock at the bottom of your screen.
18) Not Enough Memory? Check App Size and Delete. If your iPhone is low on memory, open Settings, General, and then Usage. This shows you all your apps, music, and videos with the amount of room they take up. Tap an app to see what it is using, then delete to free up memory.
19) Shake to Undo and Redo.
Shake your phone to undo your typing in any application. Shake again to redo. Your phone will pop up a query to double-check.
20) Photos Fuzzy? Try using the volume up button on the side of your iPhone to take pictures. This lets you hold the phone like a normal camera, which gives you more stability to take a clear picture.
21) Move Quickly from Camera to Camera Roll. While using the Camera app, quickly access Camera Roll by sliding your finger left to right. Keep sliding to see recent photos. Tap the screen, then the blue camera icon, to go back to camera and take more photos.
22) Zooming In. While using the Camera app, tap the screen on the part of the image you want to focus on. Pinch the screen or drag the slider to zoom in. This works with iOS 4 and later.
23) Need a Scientific Calculator?
Tip your iPhone sideways while in the Calculator app to access the iPhone's scientific calculator. Make sure you’re not locked in portrait orientation first (see 3, above)