The most well-known social network. Facebook has a lot of privacy issues, and unfortunately you have to create a personal account before you can create an institutional page.
Twitter is new and growing very quickly. It gives you a place to send out “short, timely messages” -- like little blog posts, limited to 140 characters. This limitation was designed to facilitate receiving messages from people who interest you via SMS on your phone.
Slideshare allows you to post your PowerPoint/Keynote slides. People can comment on them and embed the slide player in their own websites if they wish.
The problem with “the public” is that it’s too vague.
Create a persona -- that is, make up a character who personifies your target audience. In particular, it helps to target the power users, like the computer geeks who spend their evenings hunched over their laptops in dimly lit apartments but have a thousand friends online.
Twitter lingo: Retweeting is reposting another user’s tweet. Presumably it’s a thought you’d like to echo or comment on, or something your own followers would find interesting. It’s typical to cite the original author: “RT @sleary...”
People are identified by their usernames on Twitter. If you want to reply to someone or reference them in your own tweet, use their username preceeded by an @ sign: @sleary.
Hashtags are generally agreed-upon code names for topics of discussion. A conference might choose a hashtag and ask the attendees to use it when tweeting about the sessions or posting photos to Flickr.
All roads lead to Rome. Spreading your online presence among social networks allows you to reach people where they’re already spending time. Your user profile on the network will contain your URL, so people who are interested in you can find your home base.