I used to love using my Polaroid Camera to do quick snaps of models before doing the actual shoot and always had to use a Polaroid Back for my Medium Format camera and even a Polaroid back for my 35mm format.
But the best were those Polaroids that you watched slowly develop before your very eyes. They were never really sharp, but they had THAT LOOK. I found this great plug in called Poladroid 9.6. It emulates the look of Polaroid from any existing image you have. You have several options available as well. You can change the look of the Polaroids drastically. Have a Ball!
Hope you enjoy it as much as I do.