My bro Dave gave me some FP-3000B film. I bought and repaired a busted Polaroid 125 off craigslist to use it.
The pack film these Polaroid cameras use is peel-apart. You take the shot and then pull the film strip through rollers on the edge of the camera. This pushes the chemicals together and starts development. After waiting for the marked amount of time (which depends on ambient temperature), you pull the film apart and grab your print.
You can also scan the negatives and invert them in Photoshop, like I did with the above strip.