I tried with my iPhone 3G 8 and 16gb models and it worked fine! iOS boasts many new features, but until you are a gamer and have a iPhone4 Software, it will not be of 100% use for 3G and GS users! But looks cool though
Here, I have summed up the steps i followed.
- Update to itunes 9.2 when it asks you to do so. (Yes!)
- Let it recognize the iphone and then on itunes menu click update.
- it will take about an hour to download and install iphone4 update.
- Then Down load this file (http://appldnld.apple.com.edgesuite.net/content.info.apple.com/iPhone4/061-7436.20100621.58Yt4/iPhone1,2_4.0_8A293_Restore.ipsw)
- Then download this file http://rapidshare.com/files/401513205/redsn0w_win_0.9.5b5-3.zip (main file used to jail break)
- Wait till itunes does its job, it will back up stuff and install the new OS.
- After this is done. Unzip and open the redsn0w and select the iPhone1,2_4.0_8A293_Restore.ipsw you downloaded in step 4.
- Follow the screen steps sit back and relax, the phone will be jailbroken.
- If you notice a blank white icon for Cydia with no sources. Go to the Sources panel and add http://apt.saurik.com/cydia-3.7 repo. Now restart your phone and you should see the regular standard Cydia logo with all the sources now.
- Follow steps on http://www.redmondpie.com/unlock-05.13.04-05.12.01-on-iphone-3gs-ios-4-with-ultrasn0w-0.93/ to unlock
Resources that you might consult.
http://www.redmondpie.com/how-to-jailbreak-ios-4.0-with-redsn0w-0.9.5b5-3/
http://www.redmondpie.com/unlock-05.13.04-05.12.01-on-iphone-3gs-ios-4-with-ultrasn0w-0.93/
http://www.redmondpie.com/download-ios-4.0-for-iphone-4-9170229/