The handshake dates back 2000 years when it was quite normal to go with a sword on oneself. It was typically located on the left side of the body, and you should use the right hand to pull it. If you then have to meet anyone, or to talk to someone about some business and whatnot, you gave each other a handshake (right), and thus saw that one came with no hostile intentions. One could of course not pull out the sword simultaneously. Funny enough it has survived up until today.
In my country we give the handshake all the time. There are no differences if we meet a person for the first time or an old acquaintance, and whether it's business, casual or a formal gathering/gather. Although, very close male friends and family usually give each other a hug. Women tend to give hugs instead of a handshake, even if the recipient is not a relative or a close friend.
What tradition and etiquette do you have regarding the handshake or some other greeting ritual?