My phone display shows "Cingular" 15 miles past the Canadian border, (and then changes to "Rogers") this is all by the Champlain, NY border (going to Montreal on I-87) my question is, if I use my phone at the border itself, (or past it) will I pick up a Unicel or Cingular tower, or will I pick up a Canadian tower? does someone here have first hand experience traveling through there???
If your phone still says Cingular I'd think you're still being served by a U.S. carrier, which is very well possible. Signals can travel pretty far, even across borders. If it displays the name of a Canadian provider you're roaming.