I just found this for Canadian Citizens: (Source:
http://www.emb-korea.ottawa.on.ca/html/html1/e_menu.htm)
Canadian citizens are exempt from obtaining a visa for tourism, visiting or
business(without any employment activities) for a stay of 90 days or less.
The permission to stay for 90 days or less will be given at the time of your
entry. Those who wish to stay longer can get an extension for an additional
90 days, for a total of 6 months.
Surprisingly these are much better (and clearer) terms then those for the
US.
Hope this helps (fellow Canadians),
Avi