This thread's purpose is to provide a central place for simple answers to the single most-asked question on this board at the moment, namely "OMG! I just Upgraded to 3.1.3 without checking with people first to see whether it was safe! What do I do now?" Because the situation is different for every iPhone model, I have decided to write up a post with answers to the question. iPhone 2G Jailbreak? Yes Unlock? Yes Relax, you're golden. The original iPhone has been permanently pwned, and nothing Apple does can prevent your jailbreaking or unlocking your phone. If you have upgraded your phone, you will have lost your jailbreak and unlock, but you can easily get it back by running redsn0w 0.9.3. When it asks you to point it to the firmware currently installed on your iPhone, you will have to "trick" it by pointing it to the 3.1.2 ipsw instead. Redsn0w will jailbreak your phone and install BootNeuter, which you can use to unlock your phone. iPhone 3G Jailbreak? Yes Unlock? Probably No You can jailbreak your phone using redsn0w 0.9.3. When it asks you to point it to the firmware currently installed on your iPhone, you will have to "trick" it by pointing it to the 3.1.2 ipsw instead. Sadly there is currently no way to unlock the new baseband installed with this firmware upgrade, and for most people it is impossible to downgrade the baseband. A small percentage of 3G owners (only those who purchased their 3G iPhones in the first weeks after release) may be able to downgrade their baseband using Fuzzyband, which has just been updated to work with phones stuck on the 5.12.01 baseband. The only way to know for certain whether this will work for you is to install Fuzzyband from Cydia and try it. Sadly, if you are not one of those fortunate few early adopters for whom Fuzzyband will work, there is currently no way to unlock your phone. This means that you can only use your phone on the carrier it is officially locked to (unless your phone is factory unlocked). There is not currently any prospect for unlocking your phone. iPhone 3GS Jailbreak? Yes (updated!) Unlock? No Any iPhone 3G can now be jailbroken using the Spirit Jailbreak. See http://www.spiritjb.com. If you prefer not to use Spirit, whether you use redsn0w or blackra1n depends on whether you were previously jailbroken and have your phone's ECID SHSHs on file in Cydia (you can check this by opening Cydia on your phone and seeing if it says in green at the top of the main page: "This device has SHSHs on file for iPhone OS: 3.1.2"). If you do have this information on file, you will be able to downgrade your phone to 3.1.2 using Saurik's server to sign your install request (follow instructions here). You will then be able to jailbreak your phone using redsn0w or blackra1n. If you do not have your SHSH on file, you cannot downgrade your phone's firmware at this time, and you will therefore be unable to jailbreak without using Spirit. Sadly, whether you can jailbreak or not, there is currently no way to unlock the new baseband installed with this firmware upgrade. This means that you can only use your phone on the carrier it is officially locked to (unless your phone is factory unlocked). There is not currently any prospect for unlocking your phone.