Depending what version you have on your phone, you can use www.jailbreakme.com, slide the bar across, then let it be for 5 mins

It then jailbreaks and adds "Cydia" to your desktop

Open Cydia then click

Manage - Sources - Edit - Add

Type in http://cydia.hackulo.us and press accept/yes

Then in the cydia search function type in "Installous", download and install it

"Installous" becomes your new app store, but with a twist, every app is FREE, even TomTom sat nav for example

Anyone with a iPhone, jailbreaking is a definate must !

Theres lots of things you can change once jailbroken, adding a percentage to the battery, 5 rows instead of 4, the list is endless
This is what my home screen looks like