basically, one can post constant updates of their lives.
- right now i'm chewing bread
- i just walked to the kitchen
- opening a beer
- putting beer down
- walking to the living room
- i just stopped and thought about birds
etc etc etc
employers hate it, thee is already worklace bans of twitter and facebook in some places
So many people have, for whatever reason, taken social networking to the extreme. The concept of twitter was really pretty simple, which is probably why it was so successful. But, the user community has turned it into yet another chat tool, which actually is somewhat of a burden on its design.