I have had an iPhone for about four years now and never realized there are lots of cool hidden features that I never knew existed. Chances are you didn't either. Here is a list of some cool things.

1. You can charge your battery faster by switching your phone to airplane mode. By doing so, you shut down wireless and cellular access, which drains your battery. This will allow your phone to recharge up to twice as fast. Don't forget to switch back to normal mode after you are done charging.

2. You can find out which airplanes are flying overhead. Just ask SIRI “What flights are above me?” or say “Planes overhead.” SIRI will bring up a list that shows all the flights above you at that exact moment.

3. You can automatically turn off your music with the Iphone's built-in the timer. If you like to hit the sack and fall asleep with music playing, you can use the timer to automatically turn your music off so that it doesn't play all night. Here's how: Open the timer app, choose “When Timer Ends,” then scroll down and select “Stop Playing.” The Timer will automatically turn off your music after whatever length of time you set.

4. You can take a photo with the volume buttons. The volume up and down buttons are located on the side of your phone> Press either one, and the phone takes a picture. This is quite handy when you are wearing gloves.

5. Take multiple photos all at once. Here's how: In the camera AP, hold down the capture button, your phone will take back to back bursts (rapid camera shots), in quick succession. This is really useful if you're taking pictures of a moving subject. Afterwords, you can scan through all the shots and pick your favorite photos.

6. Display timestamps on text messages. I always wondered how to do this. Drag the text bubble to the left and you'll see a timestamp for every text message.

7. Use your Iphone as a level. very handy if you need to hang a picture. In the Compass app, swipe left and your iPhone becomes a perfect level.

8. You can start a new sentence just by double-tapping the spacebar. Try it, it works!!

9. Change the vibration pattern of your iPhone. You can alter the vibration pattern for alerts and notifications. Go to Settings > Sounds > Ringtone > Vibration > Create New Vibration. You can also customize the vibration pattern for individual contacts by following the same procedure from your contact list. This way, you can tell who's calling or messaging you just by feel. handy, eh?

10. Create a pass code with letters instead of numbers. Tired of your roommates figuring out your passcode and snooping through your phone? Go to Settings > General > Passcode Lock and turn off “Simple Passcode.” You will be prompted to change your pass code, and a full keyboard will appear onscreen instead of just the number pad. This keyboard will pop up every time you unlock your phone.

11. My favorite. Set your phone to display light flashes for alerts. Instead of having your iPhone ring or vibrate when you get a call or a message, you can have it emit an LED flash, too

. Go to Settings > General > Accessibility, then scroll down and turn on “LED Flash for Alerts." Warning: it's REALLY bright!

For more cool things your iPhone can do, click here.