96 cents.
$0.72
about 63 cents
As of January 20th, 2009, the rate to send a postcard from Canada to the US is $0.98. Reference: http://canadapost.ca/Personal/RatesPrices/Send/PostageStamps.aspx
From May 11, 2009. First-Class Mail® International to all other countries (1 oz.) is $0.98 (besides Canada $0.75 and Mexico $0.79)