I recently read a few different articles that talked about the lesser know facts of the iPhone. Thought I’d pass on two of the things I learned.

More Sensors Than You Could Shake a Stick At

We all know about the GPS and accelerometer… but there’s more sensors hidden in the face of the phone… On the face of the phone there’s an ambient light sensor and a proximity sensor (actually 2 on the 3G and 3GS). See the photo below for their precise locations.

The ambient light sensor is only used with the phone is first unlocked. It measures the light and sets the screen brightness accordingly. Hint… if you want the screen bright for a demo shine a light at the sensor while unlocking.

The proximity sensors are only activated in phone mode. This is used to detect your head. When it’s close it turns off the screen to prevent your ear from pushing buttons and to save battery life.

Like Water Off a Duck’s Back

The screen on the 3GS actually has a special polymer coating that repels oils and dirt… it’s like Rain-X for phones… The official term is ‘oleophobic’… that’ll impress your friends… perhaps more than you having a iPhone…. Want to know more… check out this Gizmodo post.

Here’s two reason why you’ll love the Amazon iPhone application (assuming you love books):

First… you’re at the bookstore browsing around… you find just the book you want… but you have a few days and want to save some money.  Use the “Remembers” function to take a picture of the item.  Not only do you get a picture stored on your iPhone but you also get the same picture stored on the Amazon website (as a new ‘wish list’) with a link to the book.  On top of that you also get a e-mail at your home account with a link to the item you took a picture of.  Score one for Amazon!

Second… I promised two… say your also at the bookstore looking for the best book on <insert topic here>.  You find a few but wonder which is the best.  Yes sure flip them open and quickly browse them… then fire up the Amazon app and quickly read the comments on-line.  When I say quick… I mean quick!  The Amazon developers didn’t just launch a Safari link to a generic mobile site… they built this thing for quick and easy iPhone navigation.  Now that you found the best book… head to the check-out.  Score one for the local bookstore!