Explanation of jailbreak for 3GS iPhones on iOS 4.0

There is a way to have a jailbroken 3GS running iOS 4.0. However, there are certain conditions that must exist :

• 3GS must be activated

• 3GS must be on a lower firmware version than iOS 4.0 and must be jailbroken, but not with Spirit

• 3GS must not have the new bootrom

If your 3GS meets these requirements then you can safely go to 4.0. Note, though, that this upgrade process WILL wipe your iPhone clean so make sure to sync your 3GS before going this route.

My 3GS meets these requirements but I have not yet gone to iOS 4.0 ... though I REALLY want to go there. The reason? MANY Cydia apps do not yet work on iOS 4.0. I use several Cydia apps and don't want to do without them so I will not be going to iOS until "my faves" are good for iOS 4.0 ... another consideration before jumping to iOS 4.0.