How to Jailbreak and Unlock an Iphone 3G running IOS 4.0

   WARNING I AM NOT RESPONSIBLE FOR YOUR EQUIPMENT AND WHAT YOU CHOOSE TO DO WITH IT.  PROCEED AT YOUR OWN RISK.   THIS WILL VOID ANY WARRANTY YOU HAVE WITH APPLE!!!  THERE IS ALSO A RISK INVOLVED HERE OF BRICKING YOUR IPHONE! 
     This instructable will be a step by step guide to Jailbreaking and Unlocking your iphone 3G running on the 4.0 software baseline 05.13.04. I used my white 16gb 3G, and unlocked it to T-Mobile.

**UPDATE**
I began to notice that my 3G was performing slower and when I investigated the matter it seems a common issue.  It would seem that the iso 4.0 is a little heavy for the iphone 3G, but not for everyone.  Some slow, some not.  I imagine that the 3GS would perform better with this. I went ahead and downgraded to 3.1.2.  This was moderately difficult to figure out, but I managed it and did a jailbreak and unlock and I am back to normal speed.  If there is interest I will add an instructable on downgrading from 4.0

Step 1 Downloading What You Need

There are a couple of things you will need to download first.
1. A copy of the 4.0 software.
   -You can find it here, http://www.iphoneheat.com/2010/06/download-ios-4/
   -This will be downloaded and saved to your desktop or like folder. You have this on your
iphone already, If not then just update your iphone using iTunes before you proceed.
   -BE SURE TO DOWNLOAD THE CORRECT ONE.  We are downloading for the 3G (see image 1)

2. You will also need to download redsn0w.
   - You can find it here, http://wikee.iphwn.org/howto:rs9
   -The download is at the bottom of the page. (see image 2)

Comments

[MrCantThinkOfAName]

Okay i know this is for the iphone, but i have an ipod touch 2g non mc with jailbroken 3.1.3. First question, is it worth upgrading for me? and two, how can i Physically backup and restore all the stuff i have downloaded onto my ipod from cydia? basically i want to know how to put all my apps and other stuff i got off cydia and temporally put it on my computer while i upgrade to 4.0 and then put it back to my ipod after i jailbreak it... Anyone know?

[mhudgens]

Like I said in my update, I found that the IOS 4.0 was a little heavy to run on my 3g so a downgraded. It did work and the app groups that you could make were nice, but not enough to keep me on 4.0. I can't speak for how it runs on ipod touch. To answer your other question there is an app in Cydia called AptBackup (search for it) that will back up 3rd party apps in iTunes. I have never used it so let me know how it works if you do.

[MrCantThinkOfAName]

I tried the AptBackup, i dont believe it is compatible on 3.1.39 which is what i have) I havent done any research to confirm that or not, but i downloaded it off the three repos i saw it on (all the same version number and not cracked versions) and they all crashed when i clicked on the app

[mhudgens]

Lame. Sorry,

[Arbitror]

*Sigh*... I still can't find a working solution for iOS MC 4.0...

[mhudgens]

Yeah, I forgot to mention that mine is MB. I was surprised though that this worked on the updated baseline.

[Arbitror]

Also, Verbose Boot isn't necessary... All that does is shows you whats going on when it boots up, just like some linux distros (without -quiet)