My wife sent me a lovely article about travel etiquette. It's well worth a read and an excellent reminder that cultures are vastly different and it's important to know and understand different ones. Me? I'm used to hugging people. That doesn't happen much here, but there are three kisses to alternating cheeks when you greet someone, as opposed to the two to four in France. Takes some getting used to, but I don't mind. When I lived in Portland, it was customary to greet many of my friends, male and female, with a hug and a kiss on the lips, but part of that was just the friends I knew and not the Pacific Northwest in general.
It's can be crucial to business and personal success to not get things like this wrong, but many people I know don't really bother to find out until they wonder why people are staring at them. Plus, it's just fun to find out about the strange customs some cultures have (shaking hands throughout an entire conversation?).