Reading and learning about stuff on the Web, trying to develop my own product to sell online so that I can quit my boring part-time job, thinking and writing about what I want in life in general and how to get it, singing, watching dumb videos on Youtube, taking long showers.
90% of the time: Reading, thinking I should be exercising, Writing, thinking I should be exercising, playing video games, thinking I should be exercising, working, thinking I should be exercising, sleeping, thinking I should be exercising, sitting on my butt, thinking I should be exercising...
2. Writing - even if only working things through in my head. Plus, I have a notebook on me at all times so I can scribble down those random snatches of phrase and plot that pop into my head. I also count daydreaming as a plot-development exercise.