If you're curious about your actual number (and how your time breaks down), you can get it with http://www.rescuetime.com http://www.rescuetime.com (YC08). It'

If you're curious about your actual number (and how your time breaks down), you can get it with http://www.rescuetime.com http://www.rescuetime.com (YC08). It's available for win/mac/linux & android. disclosure: I founded the company, love it dearly, but moved on a few years ago.