[How-To] - Jailbreak iPhone 3G iOS 4.2.1 after Erase Contents and Settings!

I have mistakenly Erase Contents and Settings of my old iPhone 3G. It was confirmed and reported a "No-no" in many posts on the Net. I made this mistake without reading any tips or warning.

Here's a method to recover my JB:
1 - Download latest redsn0w 0.9.6rc16 - see below
2 - Download iOS 4.2.1 for iphone 3G
3 - ensure you edit the hosts file and add aime "74.208.10.249 gs.apple.com" or otherwise you will get error iTunes error measage "1015"
4 - Run the Redsn0w and follow the process
5 - Once Jailbroken, install ultrasn0w by first installing its repo.

Download Redsn0w 0.9.6rc16

These are direct downloads links:

• Download now (Mac)
• Download now (Windows)

Direct Download Links for iOS 4.2.1 

• iPhone 3G

NOTE: I am very lucky that this is iPhone 3G because the final supported iOS for iPhone 3G is iOS 4.2.1 and its baseband is 06.15.00. This baseband is still being supported by the Ultrasn0w.

Jailbreak and Unlock iPhone 3G iOS 3.1.2 with Baseband 05.12.02

• We can Jailbreak iPhone 3G with 3.1.2
• Unfortunately, current Ultrasn0w is unable to Unlock the Baseband 05.12.02
• My old (USA-version) iPhone 3G has become an iPod Touch only (for the time being).
• The good news is that Sherif Hashim tweeted that the Unlock solution for 05.12.02 and 02.10.04 will only be release after iOS 4.2 is out. Most probably to avoid Apple closing the hole.

UPDATE:

• Use this Wizard to check whether your iPhone can be Jailbreak or Unlock--> Ultimate Jailbreak & Unlock Wizard