I use a Verizon air card on the road and am pleased with it, I deliver mostly in Alberta, Saskatchewan and British Columbia. Phone is ATT blackberry curve with blackberry global internet service.
Up in BC, AB, SK I am always roaming on Rogers. Verizon gets really pricy up there, don't hardly use it in Canada anymore after my $300 bill for internet service a few months ago and unfortunatly I can't tether with the Blackberry global service which doesn't cost me extra to use north of the border.