Now I want to go a little into detail regarding particular use cases:
- The main reason why Twitter was started was - as far as I noticed - to answer the question "What are you doing?".
There are plenty of other applications and services that can be used to do the same. I noticed that Facebook can be used to do quite the same. The advantage of Facebook is that it has more features and combines networking with chit-chat like Twitter without the need to go to a separate site. Even on Skype you can set a current message containing an information about what you are currently doing.
- Let others know what you think.
I think, that blogs are much more important and useful to let others know about my opinions. Twitter messages are limited to a few characters - not enough to explain personal theories or philosophical opinions.
For real chat (with single persons or particular groups) there are also plenty of other applications, this is nothing new. And again the limited message length reminds me to old days when data transfer rates where veeeery slow. Those were the times abbrevations like ROTFL or ASFAIK were invented to make the text short (and surely also to save time and effort). This is such annoying as when you want to add data in a database field and you notice it is too short.