I'm in Montreal for IETF 66. At
this point, being
able to make cell phone calls is pretty much a requirement for
coordination1. I have Sprint and
after several phone calls to customer service, I learned (not exactly
to my surprise) that roaming in Canada is fiendishly expensive
($1.50/minute). For $3/month, you can get a the Canada Roaming Package,
which reduces your per-minute charge to the still exorbitant but
much more reasonable $.30. Just so you know.
1.Mobile communications are one of those positive feedback situations. When nobody has cell phones, then people make upfront arrangements (I'll be at home at time XXX, meet you at location YYY at time ZZZ) in order to make subsequent coordination easier. But when people have cell phones, they don't bother to coordinate in advance because they figure they'll be able to do it by cell. But then if you're the guy without a cell phone it's horrifically inconvenient, so there's a lot of incentive to get one.