If you absolutely have to keep using that nexus 1, then you may be stuck with t-mobile or (maybe) at&t. Make that "trying to use that nexus 1". I reluctantly gave up on GSM phones in the US when I couldn't get signal any more. At first, everything was fine. Good signal. Solid connections. Then t-mobile "optimized" something and I rarely got signal at home. My signal at work was sketchy. The signal was fine down the road a bit. A new phone had the same symptoms. I live and work in a typical sprawled out american city. T-mobile gave me a one time refund on my bill and then refused to budge because I still got service when I wasn't home.
Yes - that's right. T-mobile thought it was perfectly reasonable to bill me because I could go down the road a mile and make a call, check voice mail, etc.
Anyways, I now have a contract with verizon. I pay more. I can't swap a phones by moving a GSM sim card. I can't play with the cool new google phones. But I -can- actually make calls, receive calls, message, use that data plan, etc.
I'm going to buy a simplemobile sim card today just to test things out.
Anyone can make an omelet with eggs. The trick is to make one with none.