Hi everyone -- I'd like to unlock my iphone to switch sims when I'm traveling abroad this summer, but I'd like to be able to switch back to my ATT sim when I get back. A few questions: 1. If I unlock it, can I switch sims back and forth with no problem? 2. Will mobileme still sync if I'm not on the ATT sim? 3. Once I unlock can I still sync with itunes? 4. If so, is it dangerous to allow automatic updates? Thanks to anyone who will answer these questions for me!!! --SR