Thumbs Up?

If you enter a restaurant in France by yourself, the maitre d' will often flash you a thumbs-up. It doesn't necessarily mean he's happy to see you.

French people who count on their fingers start with the thumb, so he's merely indicating that you want a table for one. Two would be the thumb and forefinger; three would be the thumb, forefinger and middle finger; etc.

It could be worse, though; elsewhere in the world, such a gesture with the thumb is equivalent to the American gesture with the middle finger ...