Personal Development through Twitter?

I've just signed up for Twitter and am curious about how it's going to pan out..
Is twittering be a life-improving move or a waste of time?
You can follow my twitters in the right hand column of this page (you may hae to scroll down a little) ...
If you know of an interesting twitterer, reply to this post.

Some twittererers relevant to personal development I have started to follow are:
Peter Singer
Peter Worley
Julian Baggini
Tony Robbins
Anders Holt

Let us know if you discover any other interesting twitterers ...

PS If you you want an instant ego boost, just choose to follow Barack Obama and see what happens!