I am signed up for cryonic suspension (freezing) when I die. That essay is the long, emotionally-laden plea to family and friends; Eliezer does a much better short version than I would.
I am a Singularitary Activist. The short version of that is that I work towards the coming of the The Technological Singularity (if you're familiar with the term, note that I'm of the "Intelligence Explosion" school), that I think it's the most important thing for humans to work towards, I think it will change everything, I don't believe that it will happen by itself, and I am trying to help it happen in a way that will benefit all humankind.
I have written an essay about why the singularity is so important to me titled The Future Of Intelligence. The short version of that essay is: donate to The Singularity Institute For Artificial Intelligence.