Apple ipod

What are the reasons to jailbreak my iPhone?

Is it to download it for free? Are there other options interface graphical user?

iPhone will unlock the full functionality of the phone. I used this software but sad to say, not free. If you are interested here is the link http://iphoneunleasher.blogspot.com/

How to Jailbreak 3.1.3 – Add apps without iTunes ***Complete Tutorial***