Is everything all right? In America, you might respond to such a question by flashing the "A-OK" sign, created by touching your forefinger to your thumb and pointing the remaining three fingers straight up. While the origins of the action are unclear, it appears the symbol is an attempt to create a crude "o" and "k" (the "o" is certainly clear, though not so much the "k"). This gesture is also widely used in the diving world to both ask if a diver is fine, and for the diver to respond back that she is [source: Mezcua].
Don't make this gesture in Brazil, however, where it's akin to giving someone the finger. In Greece and Turkey, it's also seen as quite vulgar, and insinuates the person to whom it's given is a homosexual. In some Middle Eastern countries, the "A-OK" is the symbol for the "evil eye" [sources: Busch, Kruschewsky].
Perhaps the worst misuse of this sign in recent history was committed by then-Vice President Richard M. Nixon in the 1950s. The VP emerged from his plane in Brazil, made an "A-OK" sign with each hand, and enthusiastically wagged them to the assembled crowd. Not surprisingly, the people were astounded and infuriated at this double insult [source: Thomson].