Given that I am in wifi coverage 100% so I do not want 3g or EDGE network on Iphone I am planning to purchase the iphone 3G from AT&T, then after 30 days I will cancel the plan, pay ETF and take the Iphone. I am using At&T Sim on my w580i, I am going to use it on the Iphone. Also, I will disable data transferring function on my At&T account. will it gonna work or is there any problem which I havent figured out yet...( I heard someone said that I must install a particular software into Iphone from Cyndia to block 3G and Edge of Iphone???) And finally, can I still use texting function after disabling the data function of Iphone?