This is a must-see interactive "slide" for any one with blood cells – that means you!. . . it takes you from the size of 12 point font down to a picometer (that's 1/trillionth of a meter)!  And along the way you pass by a blood cell, e. coli bacteria, the flu virus, an anti-body, etc.!  (Hint: move the tab below the picture).

I'm in love with this creation:    Cell Size and Scale

Thank you University of Utah!