So I'm planning to upgrade from my 3G iPhone to a iPhone 3GS in the few upcoming days. I have a few questions... 1) Should I wipe all the information (contacts, calendars, music, etc) on my iPhone prior to getting to the Apple Store? Once there is no SIM in my iPhone 3G, can I still connect it to my MacBook and clear everything on it? 2) Are they just swapping SIM cards? 3) Once I get the 3GS, I should just connect it to my MacBook, and the latest backup of my 3G will be restored onto the 3GS, correct? I've glanced over a few threads on the main page, but none seem to answer these specifically. Thanks for all the answers, and I apologize in advance if a few have already been answered.