My mom is going to be buying me the note the week after this week. She really doesn't like 2 year contracts, so she wants to buy it unlocked(she probably would have bought the 2 year contract, but she has Verizon, and another cell phone with straight talk) Anyway I already know that I would need a SIM card to connect to the internet on the go(like at school, even though I'm not suppose to have it hehe). Do I have to buy the SIM card at only AT&T?? Or can my mom like get it from straight talk or Verizon?? and if this helps I noticed there are 2 different versions of the note, and my mom is getting the European version from Amazon. Oh and what exactly is the SIM card for anyway??