The iPhone does not support disk mode, which is required to be used as an external drive.
To import photos/videos from the iPhone's Camera Roll, you can import from the Camera Roll with your computer as with any other digital camera. When there are photos/videos in the Camera Roll, your iPhone is also detected as a digital camera when connected to your Mac. iTunes does not handle the import of photos/videos from any digital camera including from the iPhone's Camera Roll. With a Mac, you can use iPhoto or the Image Capture application for the import.
You can transfer photos from iPhoto to your iPhone, which is selected under the Photos tab for your iPhone sync preferences with iTunes. You can transfer your entire iPhoto library to your iPhone, or select iPhoto Albums and/or Events only. Just as with your iTunes music - you can transfer your entire iTunes library, or select iTunes playlists, artists, and genres. The same applies with iPhoto and photos.
So it's over 3 years when this guy was wondering what would be the easiest way to transfer file video file from iphone. Issue stil persists.
Sure you can purchase iPhoto, iMovie or Aperture then import and export it.
Or you connect your iphone to Windows, open it as usb drive and drag-n-drop.
Well it's not really that simple. I need to drag my fat *** from this chair and wait for my windows laptop to boot up while I cook supper and put kids to sleep...