Pentalobular screws on my iPhone

So after finding out about these pentalobular screws, I started having a look at my own Apple products.  I found that they didn't exist on my iPhone 3G, however they do on my iphone 4S.

Here are a couple of photos:

Thanks to the macro lens I was able to get a real close up shot of the screw head.

Finding this makes me wonder what other components in products are restricting our access to fix them or if there are specific components that are not as well made as they could be.

This got me thinking about the printers they discussed in the film 'Pymarids of Waste', where they claim that there is a piece that is designed to break after so many hours of use.

Would like to investigate this further.