Eurobrat has a good post about blogging.  Read it, and be sure to read the comments as well. (Although I take issue with her computer game comments. (J/K))

Ultimately, she comes to the same conclusion I have, which is that blogging is worth doing even if no one reads it.  I read a good article about this long ago, back when almost nobody read my blog.  The advice the author gives is spot-on from my experience–writing this blog has helped me think better and more clearly about all kinds of issues.  (And I have acquired a few more readers since since I read that article!)

There really is nothing like blogging for helping you think.