An Italian couple ended up in Sydney, Nova Scotia, Canada rather than Sydney, NSW, Australia. The incident reminded me of a story that my former boss told me. He had to go to San Jose, California for work so, thinking he was doing the company a favour, he decided to buy the cheapest ticket available on Expedia. On the day of the flight, he checked in and waited by the gate. When his flight made the boarding call over the loudspeaker, he learned that the destination was San Jose, Costa Rica not California. Luckily he never boarded the plane and had to buy a second, more expensive ticket, which was the opposite of what he intended to do.
Moral of these stories: Always check your plane ticket and verify the shorthand country code and airport code.