Read the whole post in full before attempting anything!

redsn0w is an easy to use, multi-platform, multi-device jailbreaking and unlocking (iPhone 2G only) tool for the iPhone 2G (original iPhone), the iPhone 3G (but not the 3GS) and also the iPod touch (first and second generation). Currently it is available for Windows and Mac OS X (there are some issues using redsn0w with OS X PPC, please use an Intel Mac until we have this problem resolved).
REDSN0W PROVIDES SIMILAR FUNCTIONALITY TO QUICKPWN.
Official Bittorrent Releases -

Unofficial Mirrors

The following links are unofficial download mirrors, you download these at
your own risk, we accept no responsibility if your computer explodes or if it
becomes part of a NASA attacking botnet or even worse if your hands fall off
mid-way during the use of these files. We do not check these links or archives
and we accept no responsibility with regard to the validity of the files, or
with other content these links provide or with the content that is on the linked
site.  Always check the published SHA1 sums. We would prefer that you downloaded
the official bittorrent release that is linked above, but you are welcome to try
these if you really must. Mirror owners should email direct links only to
blog@iphone-dev.org , please don’t place mirrors in the comments as they will be
deleted.

Mac

Windows

 

 

 

Download iPhone OS 3.0 Build 7A341 Software Update


Download iPhone 2G Firmware 3.0
Download iPhone 3G Firmware 3.0
Download iPod Touch Firmware 3.0
Download iPod Touch 2G Firmware 3.0

You Also Need BootLoader 3.9 & 4.9 FOR 2G to Unlock It
You Can Download it:

BootLoader 3.9

BootLoader 4.6