Positive Psychology is a movement within the field of psychology, defined as "the scientific study of the strengths that enable individuals and communities to thrive" (http://ppc.sas.upenn.edu/). Psychologist Martin Seligman, Ph.D., a leader of the movement, is the author of numerous popular books on the topic, including Authentic Happiness and Learned Optimism.
What sets this approach apart from more traditional psychology and psychotherapy is the focus on building strengths and finding purpose and meaning, rather than simply diminishing suffering. In other words, let's focus on enhancing the positive experiences in your life, and not just making the problems "less bad."
To that end, here are a few exercises to try, courtesy of another psychologist, Lynn Johnson, Ph.D.: