Ok well today i waited in line for a hour and half to get my 3G iphone as a gift from my friends family. It was me and my friends dad waiting. After we had gone through a few proedures he asked my number to see if it was availbale for an upgrade and he said it wasnt so it will cosT $400 instead of the $200. But then i asked him can i use my sisters availabe upgrade and then after switch my sim card with it , he said it wont work but i find that a lil werid do you think he was lieing like can i switch sims after on iphone 3G?