Mobile disk solutions for the iPhone have been popping up all over the place since the iPhone was announced. Using your phone as a storage device is a logical extension, that until recently involved some third party applications or a jailbreak.
Apple changed that today by releasing the MobileMe-iDisk application for their mobile line. It’s free and early indications are that you need a mobile me account to use it which is a huge missed opportunity (gDrive anyone). It would have been nice if they went the same route as the AirSharing app and allowed us to connect over a wireless connection (That would probably duplicate functionality though, and Apple would have to yank their own app! Huzzah!).