And, of course, razor blades.

http://en.wikipedia.org/wiki/Razor_and_blades_business_model

I spent 6 months working at a certain razor company. I got a small discount on blades, but the razors (with 1 blade) were just about free. (4 years later - I've finished off my stash!)

Don't forget the more modern varients: PC/Internet and Cell-Phone/Calls

Yea thats true, but if buying a polaroid camera and getting say 10 pictures with it included was cheaper than buying 10 of the media seperately it would be a bit crazy, and thats exactly what I've seen with some printers recently.

disposable cameras.

Uh. Right. Because the refills for disposable cameras are so much more expensive than the actual camera.

If they sold refills at all, then the camera wouldn't be disposable, so unless this was some sort of joke...

Disposable cameras are 'recycled' i.e. refilled. They even announce this on the box.