There are times when simple really is the best. In the case of blogs, using a one-column theme can do wonders. Check out 16 Excellent One Column WordPress Themes. As Hyde says:
Tumblr and Posterous aren’t popular only because they are easy to get a weblog up and running. They are popular with lots of users because the of the no nonsense layout. No distractions, no overload of content or other items you are tempted to add. A lot of people claim that a simple weblog platform and layout helps them focus on publishing better content.
For us who still like having control on our websites and weblogs and use WordPress I scoured the web for a one column WordPress theme, which does one thing: focus on the content. And not to mention that most one column themes are minimal too, the themes to my heart.
You’ll love this selection!