Alonzo Mourning showed it takes only a moment to make life better. He played crossing guard while a handicapped person got across a very busy street. (http://sports.yahoo.com/nba/blog/ball_dont_lie/post/Alonzo-Mourning-stops-busy-Miami-traffic-to-assi?urn=nba-wp501).
You can do that, too. How? Hold the door for someone behind you, say, Thank you! when someone does something for you, just smile at someone today.
Personally, I can not tell you how encouraged I am when a scruffy teenager holds the door for me as I struggle to get my walker through a door with too quick a closer on it and the reactions tickles me when I thank them by telling them they are a gentleman and a scholar.
Try it – you’ll like it.