Originally Posted by Luigi

How to install IPhone Software 3.0 for 3G Phones ONLY

Download File from Here:

http://www.megaupload.com/?d=MMGYNKKP

Store it on your Desktop

Make sure you have the latest Copy of Itunes 8.2

Connect IPhone.

Windows.
Hold Shift click restore, find file you downloaded and run.

Mac
Hold Alt click restore, find file you downloaded and run.

DO NOT DISCONNECT IPHONE
This is the GM Edition, No activation required etc etc.
Takes about 5 – 10min to install from start to finish.