My brain tickles itself when something brand new gets invented, like a smartphone, and how different habits and customs form in each culture around that new smartphone and a brand new form of etiquette specific to each country is created all over the world. Maybe in some countries they call more than they text. Maybe in other cultures they use WhatsApp over SMS. Maybe it's e-mail. Maybe they adapt to technology's limitations. Maybe in some hellish place, phones are used openly in movie theaters.
And the best thing is, no one really knows these things! We're all aware of etiquette within our own country but completely oblivious to how third world countries have adjusted their conversations due to poor signal or how other cultures deal with how many times the phone rings and so on. Sometimes saying hello isn't enough.
Here is an infographic from Repair Labs that reveals the proper etiquette of phone conversations in different countries around the world. Are they even right? Related, I'm not sure the last time I fully said 'goodbye' as a parting remark. [Repair Labs via Visual.ly via Design Taxi]