I may be mistaken but can't you take two carry on bags on a flight as long as they fit the requirements.
  I fly every year to British columbia and have never had any problem with a back pack bag I carry on.  In it is my medicine and camera along with a light jacket.
 this year if I take my new dslr with lens I will need to carry two small carry on's if possible.  I need to check into it I suppose. :)

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