iPhone 3.0 Network and SIM Unlocked for All Carriers and Jailbreaked, Plus Cydia Installed

YellowSn0w is now UltraSn0w! So, if you have an iPhone 2.2 or prior with YellowSn0w SIM Unlock, you can restore and upgrade to firmware 3.0 now :)

You FIRST need to restore and upgrade your iPhone to firmware 3.0 in iTunes.

Then you have to Jailbreak your iPhone and install Cydia on it.

Instructions For that can be found here (don't worry about the yellowsn0w warnings!):

http://blog.iphone-dev.org/post/126908912/redsn0w-in-june

You will then need UltraSnow which you can download from Dev-Team:

http://blog.iphone-dev.org/post/128573459/ultras-now

That is all :) Enjoy your newly unlocked 3.0 iPhone goodness :)