I've lived in Chicago for a couple years now and have had the iPhone 3G since it came out on AT&T. It's pretty much a given that AT&T has a terrible reputation for dropped calls and I can attest to that. I tend to use mine more for data though anyway. In either case, can someone who lives in the area give me some advice on which carrier (Sprint and T-Mobile included) seems to work best here? I've had both Verizon and Sprint in the past but in completely different parts of the country so I'm not sure how they compare here.