LinkedIn exists to help you make better use of your professional network and help the people you trust in return.
Twitter is a social networking and microblogging service that enables its users to send and read messages known as tweets. Tweets are text-based posts of up to 140 characters displayed on the author's profile page and delivered to the author's subscribers who are known as followers.
YouTube is a video-sharing website on which users can upload, share, and view videos.
SlideShare is the world's largest community for sharing presentations. SlideShare is a business media site for sharing presentations, documents and pdfs
RSS (most commonly expanded as Really Simple Syndication) is a family of web feed formats used to publish frequently updated works—such as blog entries, news headlines, audio, and video—in a standardized format.