At one time, the Canadian and US dollars were discounted by 10 cents on each side of the border (i.e., a Canadian dollar was worth 90 US cents in the US, and a US dollar was worth 90 Canadian cents in Canada). A man walks into a bar on the US side of the border, orders 10 US cents worth of beer, pays with a US dollar and receives a Canadian dollar in change. He then walks across the border to Canada, orders 10 Canadian cents worth of beer, pays with a Canadian dollar and receives a US dollar in change. He continues this throughout the day, and ends up dead drunk with the original dollar in his pocket.
Who pays for the drinks?