To sanitize or not to sanitize?

THAT is my question. I am an avid user of hand sanitizer. A sweep through the grocery store, a stint at the gas pump, after church (**hand shaking**, “peace be with you”), after I come out of the bathroom (touching the door handle), etc. (neurotic much?). But hey, just had a debate with a friend who thinks hand sanitizer is useless. Her argument is that its the friction of your hands rubbing together that really kills the germs and that building immunities up is a beautiful thing. My argument is the overwhelming amount of alcohol that kills the germs. I know it dries your skin out like crazy, but I still find myself grabbing for the stuff all the time. Thoughts? Is it best to build up some immunities or nip that sh*t in the bud with a quick smidgen of sanitizer? Is hand sanitizer actually effective or is it similar to a placebo effect?