Want to signal to someone you've met on holiday how blisteringly all right, fine and generally okay things are? Stop! Beware of making the round "okay" sign with your thumb and forefinger. In Greece and Turkey, for example, this gesture can be taken as highly vulgar. You are telling someone that they resemble a similarly shaped part of the human body and, by extension, that they are homosexual. In some Middle Eastern countries, such as Kuwait, the okay sign signifies the evil eye.
Should you ever find yourself in an Iranian carpet souk and want to signal to the rug dealer that he's finally named a price you can agree on, please don't give him the thumbs-up. You'd actually be telling him where he could stick his offer, rather than the desired effect.
Giving someone the finger - showing them your raised middle digit, palm towards you - might be the most widespread obscene gesture in Western countries (it probably originated in ancient Greece and was spread by the Romans) but you'll find on your travels that almost any protruding digit will cause offence somewhere. In the Philippines summoning someone with a finger is considered suitable only for dogs and is punishable by arrest.
Is this the way to your famous shrine/mosque/temple? Be careful how you ask such questions when travelling. Pointing with your finger is rude in so many countries it's probably wise just to abandon the gesture altogether overseas. Use an open hand instead to indicate direction.
Burgers might have spread around the world but chowing down on one with both hands certainly hasn't. Don't eat anything with your left hand in Muslim countries or in India. That part of the body is used for an entirely different function in such places, one people don't want to be reminded of when eating.
The left hand really is a poor relation of the right in these parts of the world; you should also avoid gesturing or shaking hands with it. As a curious variation, if their right hand is wet or dirty Senegalese people will offer their right wrist for a handshake or their left hand, but with an apology.
Clearly, if you're left-handed and want to travel widely, it may be time to retrain or ask for a fork.
Young boys can hold hands without comment in Australia, but grown men? It's probably a sign that they're partners, although traditional values being what they are, still not a common one. However, such Western views may represent a minority worldwide. It's quite unremarkable to see two male chums walking down the street holding hands, or arm in arm, in India and in Muslim and African lands.
Slurping your soup - or indeed your coffee or tea - might be a no-no at your average Aussie table but in Japan it's considered good table manners. Slurping indicates you're enjoying the meal.
Arriving 10 minutes late to a dinner party or drinks bash is considered polite in Oz but it's actually rather modest by some countries' standards. An hour's lateness is standard in laidback Argentina. Even three hours would not be thought rude for some informal occasions.
And which country in the world puts the most emphasis on turning up exactly on time? No prizes for guessing the likely candidate. It's Germany.
It's easy enough to be offended in your own country by intrusive tourists snapping your photo without permission. On other occasions, you might be that intrusive tourist yourself. But the offence can go much further in certain African countries, such as in rural Ghana, where people might fear - this does make a certain sense - that by photographing them you are stealing their soul.
"Oh, I love your settee!" is a harmless compliment - and perhaps a little white lie - when visiting someone's house in the West. But be wary of making such a remark in Arab and African countries, such as Jordan, Senegal and Nigeria. Your host might think he or she is obliged to give you the item in question. An awkward situation all round, especially if you have to cart the sofa home on your back.
Anger is increasingly okay in Australia. In business if you're the boss it means you're an alpha male or whatever the female equivalent is. In more informal settings it's just showing your feelings, it's called being emotionally healthy, California-style. But for safety's sake assume anger is generally not on when you travel. Many countries around the world still put a premium on emotional control in most settings.
Your anger could be radically misinterpreted. In some African countries, such as Kenya, it could be taken as a sign of mental illness.
Be sure to check out our photo gallery with even more seemingly innocuous rude gestures by clicking here: 
Know of any other seemingly innocuous gestures that offend on the road?