A few years ago I commented on Stuart Brown's wonderful book Play and how we all have to remember how meaningful play, playfulness and fun can/need to be in our lives. Now I'm reading the recently published Lip Service by Marianne LaFrance, in which she explores the psychology, biology, and social intricacies of one of the most common of our human behaviors, the smile.

From the shy glance to the $#!t-eating grin, there is a great deal of science behind how, when, and why we smile. It's fascinating stuff - and ultimately, who cares! What I want to know is what makes YOU smile? Go on, make my day...