...and yet, if i may, Twitter is the total opposite of Farcebook, etc

Twitter turns the tawdry (i.e. personal) into the public, but actually gives very little away

one doesn't have to include much information to start, only one photo at a time, and one does not need to write a description etc, unlike a number of mandatory fields on FB

one can get to know someone through their deeds, not their details (look! he is a 26yo 6ft homosexual who likes Abba!) unless they deign to reveal these, so encourages the average user with both confidence and comfort to Twitter without restriction

as an aside, it will probably go the way of Friendster, or Myspace (very much dying a death in the UK, it seems) eventually, as you suggest. also, rather like Spotify, it's a great service, but may be elusive to try and make any money from, which could ultimately seal the deal

DC
(or http://twitter.com/dalecornish if you are that way inclined)