I tend to prefer justified text to ugly irregular line ends, but WordPress themes tend to prefer the later. Never mind, it’s actually quite trivial to fix, if you don’t mind quick’n dirty solutions.
First, note that I’m using the Carrington Blog theme. Most likely, other themes will be modifiable in a similar way. Basically, all posts are contained within a div of class “entry-content”. So all you have to do is go to the theme editor (Appearance &#rarr; Editor), find the appropriate css file (for Carrington, it’s css.php, for other them it will most likely be different but if you just search for any file with “css” in it, you should quickly find the right one), and at the end, add:
Then save, and go to your blog (you’ll probably need to purge your browser cache and refresh, aka CTRL+F5 in Firefox) to see the result 🙂