My normal work day breakfast is some type of "granola" bar.  I was talking to my sister the other day, and she suggested a Clif Bar which my brother-in-law likes Cool Mint Chocolate.  The interesting thing about this bar is that it contains Green Tea Extract for caffeine (50mg.)  My first reaction was, wow, I thought Green Tea was caffeine free, so my sister said something along the lines of, well, it should be the same amount of caffeine as a Coke, but not as much as a cup of coffee.  Another revelation, I always thought Coke and coffee had relatively similar levels of caffeine.  Boy was I wrong:

Sources: Starbucks, Lipton, Coca-Cola, Pepsi, Wilstar, Mayo Clinic, Energy Fiend, CSPI, Clif Bar