My friend did it last December (i.e.Dec. 2009). As I said previously, I sure am not on whether he did it on 2G or 3G. So, I'm sorry if it doesn't work with 3G but I have seen several people using iPhone 2G without any data plan. Once you unlock, your cellphone carrier won't know about what kind of smartphone you are using. I tried talking to my friend regarding this, but couldn't spot him. I remember he saying that he Googled the software and installed and did it within just 5 mins.  I'll let you know if i get to know from him.