Windows 7 Tip: 
Dev team Released the new PwnageTool 3.1.4 to Jailbreak for iPhone 2G/3G/3GS and iPod Touch 1G/2G. This one is only for MAC users. For best results, use the latest iTunes (9.0.1) — which includes a nice new application organizer. If you have the Legally Unlocked iphone and Want to Jailbreak the iPhone only than try this Method it will jailbreak your iphone in 30 seconds.
If your on baseband 05.11.07 thans read this Unlock iPhone 3.1.2 baseband 05.11.07 with blacksn0w
For Windows User Read This: How to Jailbreak and Unlock iPhone 3.1.2 with ultrasn0w
Here is the Tutorial:-
1. Download PwnageTool 3.1.4 here.
2. Download the iPhone firmware. 3.1.2 (3GS) here
3. Now Start the PwnageTool 3.1.4 and
Select your Device.
4. Click the blue arrow button to continue. You will be brought to the “Browse for IPSW” page. It will now automatically detect the correct firmware for your device as shown in the screenshot below.
5. Now new Windows Will come with 7 choices. Click to select General then click the blue arrow button.
6. Check Activate the phone if you are not with an official carrier then click the blue arrow button.
NOTE*: Deselect Activate if you have an iPhone legitimately activated on an official carrier.
NOTE*: You may need to increase the size of the root partition slightly. My first attempt failed at creating the IPSW until I increased the size to about 695 MB.
7. Now the Bootneuter settings are greyed out for the 3G iPhone. Click the blue arrow button.
8. Now the The Cydia settings page will come, click Download packages tab. Then click the Refresh button to display all the available packages. Double clicking the package you want will download it and make it available in the Select Packages tab.
9. Check the ones you want then continue.
10. Now the windows of Custom Packages Settings menu displays listed package settings for your custom IPSW. Leave these settings as it is. Click to continue.
11. The Custom Logos Settings menu allows you to add your own images as boot logos. Click the Browse button to select your Boot logo and Recovery logo.
12. Now you are ready to begin the pwnage process! Click the Build button to select it then click the Blue arrow button to begin.
13. After Continue it will asked to save your custom .ipsw file. Save it to your Pwnage folder you created on your Desktop.
14. Now Your IPSW is now being built. Please allow up to 10 minutes. Now You will be asked to enter your administrator password. Do this then click the OK button. You will be asked if your iPhone has been pwned before. If unsure click the NO button.
15. You will be prompted to close the PwnageTool application then put your iPhone into recovery mode. Click the OK button.
16. Make sure your iPhone is connected to the computer then follow these instructions:-
Now Open the iTunes and hold the Alt/Option key and click Restore. Now Select the custom IPSW that was created (iPhone2,1_3.1.2_7D11_Custom_Restore.ipsw) and saved it Pwnage folder ( Step 13) and click the Open button.
After this iTunes will now restore the firmware on your iPhone. This can also take up to 10 minutes. Once done you will be rebooted into jailbroken iPhone OS 3.1.2 ! So now Jailbreak is Complete
YES! Back in business, no hassles worked as smooth as silk, thank you so much you are ledgends!
Thanks man!!!! This worked like a charm! I tried different instructions from you tube and the first time I did not have a wireless signal. So I did an original restore and followed the directions on this website. Everything is a go! My 3G2 3.1.2 has been jailbroken and I get a wireless signal.
Thank you thank you thank you!!!!!!!
UH, someone failed to mention DO NOT UPDATE BASEBAND info, use baseband from 3.0 or you are SOL!
Just a note: It looks like some app suppliers are getting on the monopoly band wagon. After pwning my phone my skype app had a note saying it does NOT work with modified iphones….so Apple are attacking you from both ends….What’s new!
Watch what you buy from the app store from now on.
Well – my iTunes wants to “set up” my iPhone after restoring… It ask’s if I want to restore my old – which I don’t think I should – og if I want to set up “as new”…
After restoring, I have no data on my iPhone (mail, calendar etc.) so what do I do now?
i jailbroke using the itunes alt option thing and now ihave no service
help?
Ok… any suggestions for someone who has already updated their 3g to 3.1.2?
Just asking the basic thing… will this work for a 3GS 3.1.2 which comes from apple store with that particular software. Reply asap. Thanks.
does skype happen to work with this new 3.1.4 on 3g?
thanks 4 you help
plz let me know how i can update my jailbroken iphone (3.0 version) to the official 3.1.2 version?? will it work if i jus updated it with itunes ??? plzz reply !!
thanks
blackra1n can jailbreak and unlock 3.1.2 – 3GS, 3G & 2G.
Hi,
I just purchased an iphone 3G from ebay,.its OS is 3.1.2(7D11) and the modem firmware reads 05.11.07. The ATnt sim was provided by the seller but its nt active. i want to unlock it so that I can use it with anothe Service provider. Another issue is that I have Windows in my Laptop. Whta should i be doing to get my phone unlocked…I am really confused what to do..as differnt sites say different stuf…
Please help…
Umang