I think I've discovered the root of the problem. In the past week, I've added eleven books to my to read list, all based on reviews on blogs or other things I've read online. In the same time, I've finished exactly one book off my list.
So the answer seems to be: Don't read blogs or articles online. Instead, tackle the books on that list! Of course, I'm not too likely to do that. I think deep down, I'm addicted to adding books to my list.
Interested in where I've finding books? Some of the places recently are here and here and here.