I watched this video of a talk by Martin Seligman on TED.com (there are really tons of videos of great talks from TED conferences there). He is a psychologist and when he talks about happiness in his framework of positive psychology, he seperates happiness into three different kind of things:

  1. Pleasure – this form of happiness is about senses, emotions, makes you laugh spontaneously or giggling and is quite short-lived, heritable and not that much modifiable by yourself.
  2. Engagement – this form is about being in the zone, you are just so occupied, concentrated and engaged in a fulfilling task (be it social activity, work or a hobby). Time passes on the fly, you never feel bored.
  3. Meaning in Live – Do you feel your personal live has a purpose or meaning? Do you already know it or are in search for it? Are you content in looking for it, for all your live, or does it make you restless not knowing what your place in the universe is? This is a lot about religion and your personal life-philosophy.

You can fill out different forms at that website of his and see how happy you are… quite funny actually. And they are quite transparent, if you know the theory behind it, you see the questions were crafted scientifically.