For those who haven't tried yet. Jailbreak worked flawlessly on my iPhone 4. Unlock was relatively easy, too. http://www.techrockstar.com/wp-content/uploads/2010/06/broken-iphone-sl.jpg I also installed MyWi 4 (the major reason for actually jailbreaking my iPhone, I really need a device to tether on the way) and My3G. Besides, I've installed Open SSH server and SB Setting, to be able to turn the SSH server off. After that, problems started to appear. The biggest one was FaceTime turned off and not being able to turn on. It actually started to send freaking short messages to some +44 number (I guess I'd be quite upset with upcoming AT&T bill), and I started to receive some replies back. Installing iPhone Delivery (which was recommended to early users of jailbreak) didn't solve the problem. I stopped receiving replies (although, I'm not sure I'm not billed for them :), but FaceTime failed to activate. Uninstalling My3G did the trick. Easily activated FaceTime after that, and it started to work well. Reinstalling My3G after, kept FaceTime activated, but every time I tried to connect thru FaceTime it was failing. So, I'm ending up with no My3G, which makes the overall experience less exciting, but I hope this problem can be solved soon.