Ok this is for people who have iPhone 3GS’s. If you do not care about jailbreaking and unlocking your phone, then this isn’t for you either.
1. What is an unlock? An unlock basically allows you to pop in a different SIM card from a GSM carrier (T-Mobile, AT&T in the U.S.A, sorry Verizon).
2. Why is this important? Because, if you go overseas, the rates for data is astronomical. When I went to Amsterdam, AT&T wanted to charge me $20 dollars per MEGABYTE. I used 20 megabytes in less than 3 hours. Under AT&T’s plan that would have cost me $400 bucks.
3. What is a jailbreak? It allows you to install software not supported by Apple. For instance, an unlock program to allow you to use other SIM cards.
I unlocked my original 3G iPhone because I was an idiot and upgraded to 3.1.2 on my 3GS. I bought a vodafone prepaid sim and popped it in. Sent an SMS to a special vodafone code and got unlimited internet for about $15 USD for 30 days. I only needed it for 7 but still. $15 for unlimited as opposed to $400 for 20 megabytes. That’s a difference.
NOTE: YOU CAN NOT UNLOCK YOUR 3GS IF YOU ARE ON 3.1.2 CURRENTLY. However, you WILL NEVER BE ABLE TO UNLOCK EVER if you are NOT JAILBROKEN.
Which brings me to the point of this message… Apple is gearing up to prevent jailbreak’s altogether. They have already patched the bootrom and newer 3GS’s can NOT be jailbroken at all right now. However, if you have an older 3GS and wish to jailbreak, now is the time to do it, or else you may NEVER be able to.
For the super technical: “Note for 3GS users not already jailbroken and stuck at 3.1.x: this version of PwnageTool has a side feature to jailbreak your 3GS. It uses a simple implementation of the usb control msg hole found by chronicdev, geohot, and our very own gray. Now that the hole is public and in use, we expect Apple to close it by the next major firmware update. That’s why 3GS users need to get their ECID hashes for 3.1.x now, and need to stay onboard the “jailbreak train” in all future updates. For more details on what this means, please see our earlier posts or ask in our comments section (moderated by the always helpful @angie and @confucious!).”
So, go do it if this at all sounds like something you might need to do in the future.