Also I have been contacted by a number of you who have told me that you have had a headache since Monday.  In most cases this is a result of reducing your caffeine intake.  I assure you that this is not dangerous at all.  And today should be the last day that you have a headache so hang in there.  It is called a "rebound" headache.  Caffeine is an effective vasoconstrictor.  That means that it reduces the size of your blood vessels.  Reducing the size of these blood vessels can increase your blood pressure and cause damage to your cardiovascular system.  When people use substances such as caffeine which cause vasoconstriction your body reduces the amount of natural vasoconstriction that happens.  When you take the caffeine away then your blood vessels do the opposite of vasoconstriction: vasodilation.  The headache is caused because the vasodilation is so extreme that it stretches these blood vessels and that causes pain.  Within 3 days your body should be making enough serotonin to counteract this effect.  

So hang in there!  You body is sending help!

Check out this video clip from CNN about Caffeine Withdrawals: