A question for those familiar with AT&T and the options for porting. I will be getting my iPhone 4 soon (or eventually). I want to try it out, and I don't want to ditch my old Virgin Mobile phone just yet (lame phone, but cheap and reliable service). So I don't want to port my number over immediately. With AT&T, can you port your number after the fact. Like, say I'm using my iPhone 4 with it's new number for 2-3 weeks and I decide I'm happy with the service/phone and will be keeping it, can I then have AT&T port my Virgin number to my iPhone, essentially changing my number?