We just got back from a cruisetour on the Dawn Princess. For those of you who are wondering about cell phone service here's a list of where I did and didn't have service with AT&T/Cellular:
I had service in:
Vancouver
Ketchikan
Juneau
Skagway
Copper Center (Princess Copper River Wilderness Lodge)
Denali National Park
Anchorage
I didn't have service in:
Whittier
Glacier Bay (obviously!)
College Fjord (obviously!)
I bought a phone card and never had to use it.
If you have any other questions about anything please feel free to contact me.