I would like to pause and point out to all the rationalists out there...As far as we've been able to tell, among the strongest predictors of happiness yet discovered is the extent to which one feels regularly grateful. Exercise and friends are also near the top of the list.
And so, if nothing else...use today to actively experience the emotion of gratitude, and perhaps even set in motion the beginnings of a habit.
Relevant to this blog, I am grateful for the luxury of a truly excellent commentariat and readership. Civilized and always thoughtful, even in disagreement, is most of what a body could want.
EDIT: Tabarrok brings the science (really, just one of many studies. I'd strongly recommend the book: Destructive Emotions).