How often do I journal?

I keep 3 journals right now. I write these as notes to tasks on www.rememberthemilk.com

• Gratitude
  Here I list up to 5 things that I am grateful for either that day or the day before depending on if i do it in the evening or the morning. I find this helpful in that it gives me a perspective on my life that things that I wasn't grateful for in the past I wouldn't live without now.
  
• Daily affirmation
  This is my daily congratulation to myself for what I will accomplish. I note here how awesome I feel for the accomplishments that will happen.
• Habit Journal
  this is my record of how I am doing building do habits. This is to encourage me to improve my life, one habit at a time.

Journals I have written in the past include:

• Meaning
  What is meaning? What I have I done to create meaning, what will I do to create meaning? This journal which I keep off and on (Put it aside for a while when I get numb to it) is a detail about how I feel about meaning and what meaning is.
• Purpose
  What is my purpose? How do I define purpose?
  This is one I will be relaunching soon to explorer the purpose statement I developed before.
  
• Daily Record
  This is one I have done off and on but not because it goes numb. I have procrastinated and argued with this journal since I discovered it. I did not have my !daily list last time I kept a daily record. I will add it to !daily right now. The first entries will consist of defining the purpose of the journal.