So you have heard all the press about Twitter right? But you don't know what Twitter is or why should care?
Twitter is a web application that allows you to network with your customers, or friends, by posting short messages (limited to 140 characters). It is different to sending email in that your messages can be publically available to all those that search twitter.
People who are interested in what you have to say can follow you on Twitter. Depending on whether they use the Twitter website or a special Twitter client on the computer or mobile phone, they can receive your short messages as a way to be updated on what you are up to or with any new announcement that you wish to make.