With www.jailbreakme.com jail breaking an iPhone suddenly became too easy not to do. I’ve jail broken iPhones before with ultrasn0w but this is too simple. Just go to that site on your pre-4.0.1 iPhone, slide your finger across the screen and you’re done.
Simple! But what next?
Your new app installer is called “Cydia”. It’ll be on your home screen. Go play with Cydia and install some apps. Not all are free and none of them are approved by Apple. Now that you can install anything on your iPhone you need to be a little more cautious. It is no different from downloading apps from the web and installing them on your computer — the code is not vetted by any single governing body and you need to be thoughtful as to what you’re installing.
First thing is to fix the root password. iPhones have a default root password of alpine. So install “mobile terminal”, open it and type “passwd” to change your password. Alternatively, connect to your home wifi network, install openssh on your iPhone then go to Settings -> WiFi and take note of your IP address. Then from your laptop ssh into your iPhone and change your password with the passwd command. Also change the “mobile” account password with “passwd mobile”.
Next install the PDF Patch fix (since that security vulnerability let you jailbreak your iPhone via jailbreakme.com in the first place).
Now follow these simple steps to unlock your iPhone so you can use it on different networks.
Finally, go have fun. Change themes, message alert tones and customize to your heart’s content. When new versions of IOS come out be sure to download and jailbreak before you install them to your device. Don’t just click “install” in iTunes.