The other day was talking about the Iphone 3G and showed you a review from a youtuber who has had for a while. It looked really impressive from what I saw in the specs and the review that was done. I was watching a Blunty3000 video (A Youtuber I got a lot of respect for) saying that the Iphone has an application that can make Iphone and Ipod have a WiFi Harddrive and its called Datacase.
I'll let the video explain.
Blunty3000's Youtube Channel