I find small gestures very exciting. I spend a considerable amount of time thinking about why people make them and the various meanings they have.
First of all is the wave. The single wave which signifies the final goodbye. The wave at the railway station which involves the whole arm meaning goodbye and I'll come back. The simple show of the palm without movement which probably says simply OK bye then.
Interlinking of fingers and rubbing the thumbs together which mostly speaks of not knowing what to do and sometimes of impending tense time.
Looking directly into the eyes of someone as they speak and then looking away most of the time brings a pause to the conversation or changes the subject. Holding your face within your palms simply means you have little to say as it actually makes speaking difficult causing your face to bob up and down.
The head turn is one of the most exciting ones. As you walk behind someone they turn around hearing the sound of your shoes or just sense your presence. A smile may or may not follow depending on the mood and familiarity of the person you are following. A lot of times if the woman in front of you has a good head of hair she will swish it as her head turns back to it's original position. Then there is the head turn at the curb when someone who nearly disappears at the corner glances back to see who is behind him or her, this is simply out of curiosity and almost never involves a smile. And then there is the lovers' head turn when a member of the opposite sex turns, looks, barely smiles and then continues to smile when their face is safely out of vision. This is very exciting for other people as the object of affection is unable to see nearly half the gesture.
Then there is the kiss kiss gesture. When you meet someone they kiss the air around you twice involving no actual cheek touching. Considering how intimate kissing is this one is a very formal gesture and needs expert co ordination as a lot of times heads bang into each other if you go in the wrong direction which i do a lot. I personally prefer hugging which is a more casual and affectionate gesture bringing about instant good feelings.
That's all for now. I will add to this as more gestures come to mind. Do you have favourite gestures?