I have a 7 hour layover in Toronto before my international flight. I arrive at 2:15 pm and my flight leaves at 9:15 pm. I don't want to spend the entire time in the airport. What options are there for sightseeing or maybe some shopping? I've heard about Kensington Market, is it easy to get from the airport or is there a closer shopping destination? Also, will I need to change money or can I use US dollars?