Wait a second guys, everybody is talking about completly different areas. The NNew York metro area is fine for At&t. I just switched over from Sprint and now use At&t. I have done way to much research and found that it doesn't matter which phone you use. Only certain areas have a good GSM network capable of higher speed PPC connections "19kps" but any phone will work on a network dependant on you telephone you can get speeds around "5-9kps".
but the best thing to do is to check you carrier, find a phone your like with all the features and then go onto
www.supplynet.com and get a single cable for $59 us. It is better than using a $70 us mu;lti connect erial port kit from what manufacturer and getting a RS 232 adpater from compaq to connect to the serial port adapter.
Until the two bug US carriers go GSM fully (Verizon and At&t) we are stuck with the terrible service of Sprint, Voicestream etc. there are other broadband wireless service providers on the way (worldcom, quest and a few others) but it will be almost a year away. In the meantime those of us here in NY should get the cable from Supllynet and service from one of the five carriers her in the metro area. One final thing to take into consideration around the entire US is that all the carriers have switched to 9:00 start times for their nights and weekends. Only At&t has kept the 8pm night and weekend start time.
good Luck any more questions I would be glad to anwser. someone should benefit from my weeks of research.