Author Scott Berkun says writer's block is really fear of
writing something crappy - and offers some tips for getting past
the anxiety. My favorite is flipping your self-doubt over on its
head and using it to get started:  Write about how it feels not
to be able to write. It's sneaky, but damn, it works. The voice
in our heads is always saying something, so get it down. Imagine
yourself as a recording device, writing down the radio broadcast
of some other person who happens to live in your head.
Eventually your mind will hit thoughts on the topic itself and,
presto, you're on your way.  That first word really IS the
hardest - so any way to trick yourself into getting it down is a
godsend, whether you're a college student starting a paper, a
blogger who wants to update, or a famous published author.