Greetings are always a curious part of any language. The Hawaiians have ‘aloha’ which means ‘hello’ and ‘good bye’ as does the Italians’ ‘ciao’. The English – as in what people in England speak – have an all purpose word ‘cheers’ which can not only be used as ‘hello’ and ‘good bye’, but also ‘thank you’ and ‘you’re welcome’.
Dhivehi is the native language of the Maldives islands and it has no direct translation for ‘hello’ or ‘goodbye’ (http://en.wikipedia.org/wiki/Dhivehi_language). Instead, islanders greet each other with a smile or the raising of the eyebrow and just ask "where are you going?" followed by "what for?" The tradition evoked for me one of the earliest ever Dilbert cartoons show above (featured in Dilbert’s ‘Build a Better Life by Stealing Office Supplies’).