Hey, I have an iPhone 3G, and jailbroke it using blackra1n awhile back. I am on software 3.1.2 and don't know anything about baseband. I tried to make sure not to upgrade at a time when I read posts advising not to do so because it would then be irreversible and could no longer be unlocked? I didn't really understand it at the time so I went ahead with the jailbreak which people said was fine, but didn't do anything else since then. With the new iPhone 4 coming out, I'd like to sell my current iPhone and use the money to upgrade to the new iPhone. Now, I'm not sure how to maximize the value of my phone. I think I've read people pay more for jailbroken + unlocked phones. If that is the case, what should I do? With the new OS, can I upgrade to the new OS through itunes, jailbreak, and unlock? Can I only upgrade to the new OS and jailbreak, but not unlock? If anyone can walk me through this, it would be greatly helpful, especially because when I read other threads I don't seem to understand what's going on when basebands are mentioned...?