"Volunteering - A Great Way to Learn Real Executive Leadership" by Karl Moore. Not only is volunteering good for the community and not only does volunteering make you feel good about yourself, but it's also a great way to build transferable skills. ;)
The Social Media Revolution – A New Era in Marketing - infographic + video - How social media is changing the world
Brian Solis knock off. A bit easier to read. Some of the media could be in multiple categories, but it's a good framework for thinking about what you're doing with each too.