I have been using this for a while, ever since I installed outlook 11. I find it very useful for remembering things I need to do.
When you get a mail, just single click on the follow up flag to mark it with a “red” follow up tag. I often use the different colors to mark things with different order of importance - red is if someone is dependent on me to do it, or if its really important, and say orange is if its information I should read about but its not terribly important right now...Every day in the morning, I go to the Follow-Up folder, which is a new folder view in outlook 11 that just aggregates the mails with the follow up flag on them all in one place and groups them by flag color. If I can follow my list, I feel extremely satisfied once I check off a few items off my list. You can also set reminders, its just wonderful!