I got a big scar today. I was playing around with my iPhone and trying to free up some space on the root disk [ disk0s1]. So I was moving stuff from the [/System] folder into the media partition [/private/var]. I moved the Fonts (85 mb) and the Framework directory and things still looked fine. But then I rebooted the iPhone something was very wrong. The iPhone failed to boot and ended up in the console no key input was possible and iTunes couldnt detect it so restore didnt work. Nothing i did helped and I was really worried that I just bricked my phone. After some googling around I found out that you can put the iPhone into somethink called DFU mode boot into a state where you can restore it from iTunes

After some googling i found this very helpful tip to restore the firmware to is original :

Step 1. Turn off your iPhone.

Step 2. Hold Power and Home button, the iPhone should now be boot.

Step 3. When you see the Apple logo, release the power button but HOLD the home button.

Step 4. Open iTunes and wait for it to tell you in restore mode.

Also, NTL leave a comments to stated that how to put the iPhone in DFU mode easily. Take it as an alternative method if the above does not work for you.

Step 1. Connect iphone to USB then listen to the sound when it connect and disconnect.

Step 2. Hold 2 buttons until hear disconnect sound then release power button.

Step 3. Wait until hear another sound then release home button