Using pwnage tool (or blackra1n too I suppose) - if your iPhone is already activated, when you upgrade to a new firmware and jailbreak, assuming you're not using an official carrier do you need to hacktivate or will iTunes remember the old activation when you restore from previous backup? It's an issue because now my phone was "officially" activated, so Push works no problems. I'm on T-Mobile so I'd need to hacktivate if I had to activate again and I don't have an AT&T sim around anymore...
I'm pretty sure you don't need to, but was just looking for confirmation!
activation is pretty useless if im not mistaken.. its simply a step that apple put in place to essentially brick your phone until it connects to a legit carrier.. either using a att sim or hacktivation, i dont think it really matters.. dont quote me.. lol.. But i dont think its anything to worry about..