It's official, swapping skills and exchanging favours actually makes you happier. Dr Tal Ben-Shahar, Happiness Expert and Positive Psychology lecturer at Harvard University has written a book called 'Happier' which is based on the latest, leading edge research on what makes human beings happy. A quote from the book:
"Helping oneself and others are inextricably intertwined; the more we help others the happier we become, and the happier we become the more inclined we are to help others. Contributing to other people's happiness provides us with meaning and pleasure, which is why helping others is one of the essential components of a happy life."
Dr Tal Ben-Shahar, Happier
So find a friend, do them a favour and get happy!