Twitter is a web site that offers social networking and a micro-blogging service. It is a worldwide site used by more than 100million users
RSS (really simple syndication) streaming news, this is a free web free set up by many major web browsers.
Instant Messaging
MSN
Social Networking (facebook)
BBM (BlackBerryMessenger)
In Game chat
Advantages
Real time
Global
Easy- Voice, Video, (iPhone4)
Disadvantages
Privacy
Spelling
Open to abuse
English/ Language