Enter an area code and then pick a town to see the local calling areas.
It might be useful to frequent travelers. Cell phone companies don't seem to mind what area you choose as your local calling area. Some places seem to "bridge" a few areas.
Example: (according to the info on the site above)
Say I live in Miramichi and I call or visit Tracadie-Sheila regularly (they're about one hour driving distance apart). If my local calling area was either of those then calling the other would be long distance. However, if I choose a Neguac phone number then (according to the info on the site above) calls TO or FROM Miramichi or Tracadie-Sheila are local.
If you have a good long distance plan then you might not consider it. Our "spare" cell phone is pay-as-you-go and long distance (within Canada) is 70 cents a minute so the savings from having an optimal local calling area could add up.