The real issue is not whether I need to be able to use the Internet while I'm on the phone, but whether I need to be able to get a call when you're using the Internet. It works both ways, you see. If I'm away from home streaming Pandora on my iPhone, I don't want that to mean every call I get is going to go to voicemail. Back when I only had Edge at work I was forever missing calls because I was on the Web or watching a video or even just because my phone was polling email. With 3G I no longer have this problem.