http://www.linux-tips.org/article/99/using-iphone-internet-sharing-over-bluetooth-under-linuxUsing iPhone internet sharing over bluetooth under Linux
To use your iPhone's internet connection through a Linux notebook over bluetooth, you have to open Tethering option on your iPhone device, under the Settings->General->Network section.
After that you can install blueman for easily configuring bluetooth PAN network:
apt-get install blueman
Start blueman-manager and find your mobile device and connect to it. When connection completed successfully, select Device->Add->Network Access Point in blueman-manager.
And the last step, configure the network interface:
dhclient bnep
