I decided to research this up a bit, and here's my stats: Now, there is one flaw in my math. The flaw is the total people I have at the end of each addition. See, I added up the number of people covered by the carriers AND the number of people covered by it's roaming partners to get the total number of people it can cover. The flaw? Well, there will be lots of over-lapping in coverage. For example, Cingular and t-mobile will both have coverage in say New York city. So since cingular covers 9 million in New York, and so does T-mobile, adding 9+9 together isn't really the right way to do it. Because it's not really reaching 18 million people, just 9 million, as both carriers are overlapping and having coverage in the same spots. So although it's off, it was the only way I could figure it out because of so many carriers having coverage in the same spots. Cingular Cingular's standard GSM voice service reaches 270 million people. Now if Cingular roams with t-mobile, that means potential 270 million from cingulars coverage + 275 million from t-mobile = 545 million people Verizon Verizon offers standard voice coverage to 255 million people, but 291 million people if you include it's roaming partners. Sprint Sprint's standard voice service reaches more than 295 million people + roaming. Since sprint can roam off Verizon+Alltell, add 255 million from Verizon, and 72 million from Alltell. = 622 million (plus analog roaming) Alltel Reaches 72 million people off Alltell network. + roaming from Sprint (295 milion) + Verizon = 255 million = 622 million T-mobile T-Mobile reaches 275 million people + roaming from cingular (270) = 545 million Nextel Nextel iDen network reaches 264 million people. So from that it seems like: #1= Sprint and Alltel #2 = Cingular and t-mobile #3 = Verizon #4 = Nextel (information above thanks to: http://tech.yahoo.com/blog/null/3554) BTW, does anyone know who Cingular roams with? I know they roam with t-mobile, but I wasn't sure with who else. Because if you have Cingular in a small rural area, and there is no t-mobile signal either, who will Cingular use to roam off of then? Or will it be no one, and you'll just have no signal?