Please don't flame me but, I just want to get a quick answer to this question. I have a 3G iPhone, and I have successfully jailbroken it several times, and I know the do's and dont's of the process. But recently my friend asked me to jailbreak he's 3GS and I hear that there are some... limitations/quirks?

So, how is the jailbreak process different in the iPhone 3GS as opposed to the 3G? Is there something that I should be aware of?

Thank you.

If they still running 3.0 or 3.0.1 it is pretty much the same procedure. Just a warning to them to be very careful when installing programs that modify the built-in OS from Cydia as it is not possible for them to restore their OS to 3.0 anymore, only upgrade to 3.1 and there is no jailbreak yet for 3.1 on 3GS.

Things that are based on mobile substrate (SBSettings, winterboard etc) should be fine as mobile substrate has a safe mode if things go wrong.

also make sure you download the correct 3GS firmware and not trying to jailbreak a 3GS with 3G firmware.