The document lists 20 popular social media platforms and provides a brief overview of each one, including their logo, target audience, overall purpose, and in some cases alternate uses. The platforms covered include About.me, Blogger, Box.net, Delicious, Digg, Facebook, Flickr, Foursquare, Google Plus, Klout, LinkedIn, Pinterest, Skype, Slideshare, Twitter, Tumblr, YouTube, WordPress, Vimeo, and Yelp.