Maybe I'm being dense, but I'm not quite sure how you safely upgrade the 3G to FW 3.0. I've gotten burned on this before with 2.2 and I don't intend on doing it again.

First it says to upgrade your firmware to 3.0. Upgrade it with official FW through iTunes? Does it require any preparation beforehand? (Baseband, bootloader etc.)

So basically am I missing something or am I just being paranoid and it's safe to upgrade and do the sn0w?

i have update the software to 3.0 without doing full restore (i want to keep my apps)
and afterwards jailbreak and unlock (removing yellowsn0w first)

all is working fine...

do we have to do a restore or just update? which choices is safer? maybe someone could give advice, because the device is jailbroken on 2.2 and jailbroken again in 3.0 would it make the file system corrupt or crash?

thx for sharing your thoughts

interesting question.. maybe u could try to backup your iphone first before doing an upgrade to 3.0
or maybe any other idea?

i have lots of apps installed using "mobile installation patch"

of course i do backup first

i think that using update and jailbreak "again" (because it has been jailbroken before on 2.2.1); will make the iphone file system crash, but on the contrary... everything works fine...

all apps is working, no need to do "mobile installation patch" again...

but i still doubt if the best one is to restore and install again all apps or just update and jailbreak again...

There are some excellent video tutorials on iClarified - Apple News and Tutorials on exactly how to unlock your 3g phone.