I normally don't skip updates. I did skip over 4.0.2 I think it was. 4.1 and the upcoming 4.2 offer some speed improvements for 3G models. Sn0wbreeze is nice because it doesn't update the baseband. iTunes updates the baseband which means you lose the unlock for now and possibly forever. Although they have unlocked it everytime.

With Sn0wbreeze you download a copy of the ipsw then open it in Sn0wbreeze and it creates a custom firmware. You then use iTunes to update by using shift click restore. NOT UPDATE. Once you hit shift then click restore an box pops up and you navigate to the location of the custmon firmware. Select it then iTunes takes care of the rest. Once done you have a jailbroken iPhone with an unlockable baseband.

I will update to 4.2 when it comes out using Sn0wbreeze cause they beat most everyone to the punch and it works. Plain and simple.