Great reasons to start a blog from lifehack.org
For people who wonder, “why blog?”, the people at lifehack.org have listed
a number of strong reasons why you should in their article, How To Use Your Blog To Make 2008 Your Best Year Ever!
The article is written from a viewpoint of how to use a blog to improveyourself, and the bonuses they list regarding blogging (e.g. trackprogress, get feedback, share knowledge) apply to anyone, either personally or professionally.