Especially useful for reloading Instamatics, since the film is getting hard to find. See my Pocket Instamatic Instructable.
Just get a few used one-time-use cameras free at any photo lab.
I prefer the ones without a flash, but I take what I can get.
The shock you get from the flash unit is molar-melting, so play it safe and get the outdoor, sunny-day, no-flash type cameras if you can.
You'll also need a pack of snap-off cutters from the dollar store, some 5 minute epoxy, a metal nut, and masking tape.
Step 1: Gut the Camera
Peel off the paper cover.
Next, remove the front by gently prying up the latches on the sides.
Discard the flash unit and be prepared for you WILL get shocked.
Remove the two plastic flaps on the camera bottom, the inside mechanisms and optics, and back cover.
We just want the camera as a film holder.