Hello, I'll teach you how to successfully install and use Bluetooth on your Raspberry pi. Just a heads up I'm assuming you have a version B and you've setup your raspberry pi already (for system preferences and ect.)
Step 1: Hardware
1. You'll need a raspberry pi B (if you don't already have one)
2. A Bluetooth dongle I recommend http://www.adafruit.com/products/1327 it's what I'll be using.
Step 2: Software
You're going to need to be in the terminal and type: sudo apt-get install bluez-utils
Next type: sudo apt-get install bluez-tools
After that type: sudo apt-get install blueman
Reboot the Pi then put the Bluetooth dongle in
Once done type hcitool scan into the terminal it should immediately send feedback which means it's (hopefully) working!!
Then type: startx
Step 3: Wrapping Things Up
Once it's done loading you should see a Bluetooth symbol in your tool bar or task bar (it looks like the first image in this step FYI) then right click on it and hit make discoverable your iPhone then will have 30 seconds to search for the pi. So on your iPhone have settings/Bluetooth open and make sure it says "discoverable". Then (image 2, name of your pi)-0 should show up then tap on it. On your RPi it should say something like Bob's iPhone then give you a confirmation code and your done (or connected) so tethering, pairing, and file sharing should work! Enjoy!!!!!