I used lock iphone 4 in the psat. That is really bad! I really hate it. Because it not only has a lot of problems. And it is not convenient when I am in business out of home. So I often take two mobile phones in my bag. That feeling really heavy and very vexed. I hear from my friend said ecwhole stores sell original unlock iPhone4. And the price is cheaper than any other store. I gone to ecwhole of store and bought an iPhone 4 factory unlocked Mc605b/a as quickly. I spent $567 to buy it. Now I no longer for the mobile things and trouble! Feeling pretty good !