airPort personal iCloud?

In theory, yes.

But, you might not be aware that the hard drive port on the AirPort is USB 2.0, and that it runs at about half of the speed of a USB 2.0 port on a computer, so things are going to be mighty SLOW when you try to back up or access the drive.

Actually, I have been using it since 3 years ago. On my Mac Pro I simply created a shortcut on the finder and on my iPhone I access files using an app called FileBrowser. It's not that slow to be bothered. I have HD 16GB movies to play whichplay with a little delay, but pausing the movie for a minute or two fix the problem. However movies less than 8GB are being played smoothly. For me, accessing movies on my network are more important, but you may guess other files are so easy to reach. There are some files that I sometimes want to access over the internet. I heard it is possible by Back to my Mac. But I really don't know how.