Was the iPhone originally a flip phone? Apparently when Apple filed the patent for the proximity and light sensor for the iPhone they still weren't sure what it was going to look like.

The patent goes on to describe how the phone senses the activity of the user and how it is to react. You'll also find information pertaining to how the AI, accelerometer and other sensors work on the iPhone.

I still think that it is rather interesting to look at some of the different designs Apple had in mind when designing the iPhone. Just look at the size of that old candy bar phone, I doubt that Steve Jobs could manage to sell 10 thousand of those, let alone 10 million. One of the designs does resemble the iPhone that we've come to know and love. The big change is that at the time of filing, they considered offering an optional antenna on the top of the phone.

Apple's iPhone light, proximity sensor patent [via macnn]