These days you're right. Most people everywhere would probably recognize it. However, it's not the one they would all use. In some countries it's the little finger rather than the middle finger. In others, it's a larger, more public gesture: Raising your fist with the back of your hand toward your target, your elbow bent, your other hand grasping the horizontal upper arm in the crook of your elbow. How many of you can do the "Vulcan finger"? My own invention which I can do after years of practice: Do a Vulcan "live long and prosper" salute with your middle finger and ring finger separated. Then curl your index finger and your little finger down, leaving your middle finger and ring finger making a V. A guaranteed way to induce fits of laughter in any Star Trek fan.