Twitter is a microbloging site that started out as a way for some friends to quickly update each other. The more geeky crowd jumped on it as a way to share events, find those nearby for lunch and just provide short comments. It has presently exploded into a publicity engine where celebrities have tens of thousands of followers, people who want to read what is posted, and several million users. I too have an account on twitter and update it with comments, pictures and status updates. It can be used as a rescue tool, as demonstrated by the student who was arrested in Egypt and was able to get help from the embassy quickly by posting messages to his friends on twitter, news was broken about the earthquake in China, news agencies used it to pass status information about fires in southern California and one person even used twitter and ustream to share the time a drunk walked into his house at 3am.
One thing to remember about twitter, facebook and social web sites in general is that people use the service their friends are on and not all of them. This can be a time sink, as was email, the telephone and the television. This too will be shown to be useful as a communication tool.
The process of posting to many sites, so that you get the message to many patrons, can be streamlined so that one post can be sent to many services.