As you may already know, the number of Polaroid cameras still in operating condition has been an issue since the dudes at Impossible Project brought it back to life. And since the sales of the print film is what they are after, why not hit the iPhone crowd for money?
All you Need is an App & Film
A total no brainer here. The app works like an exposure timer while you manually open the shutter on the print film device. Push the button to eject the print when exposure is done. and that's it. Battery power comes from the battery embedded on the Polaroid film cartridge so the printer doesn't do anything. It is totally dead and functions as an oversized paperweight until you get an iPhone and a pack of Impossible Project Polaroid film.
Now I have issues with the Impossible Project film quality. It is not entirely the best compared with the original Polaroids but heck, you don't care about that. What you need to know is that your spiffy iPhone can churn out Polaroid prints for all you buddies. It has to be an iPhone as it has been made to fit the screen size.
That said, I think you'd be better off with a 4R Printer from the Canon Selphy or LG Zink Pocket Printer line. The Canon prints are probably cheaper than the Polaroid ones too and the Zink ones are even cheaper than the Canon ones.
The idea behind the Polaroid is a nice one but wait till the large screen iPhone comes out. It will throw a spanner in the works for things like the Polaroid Instant Lab.