Here is an app with name of “PhoneDisk” that allows you to transform your iPhone into an external hard drive. This app is available for both Mac and Windows. You can directly preview, open, edit, and save images or documents on your iPhone. The best thing of this app is, it is available for free until December 1st, 2010
Simply download the app, and then use this key to unlock all the features for use:
How It Works:
Just connect your iPhone to your computer via USB and then launch PhoneDisk app from computer and after it you will get access to all folders. If you want to get access on system files or other files which were not related to media then you must have a jailbroken device.
Download PhoneDisk From Official Website