Ahh, this is the basis for part of my favorite pg essay, "Good and Bad Procrastination".

http://paulgraham.com/procrastination.html

pg condensed Hammings 3 questions into one:

What's the best thing you could be working on, and why aren't you?

I haven't used a "to do list" since. I keep working on my most important thing and when I'm done, I just pop the stack. What a difference.