Run right out (okay, in the morning is soon enough) and acquire a copy of Rebecca Skloot's _The Immortal Life of Henrietta Lacks_. Right now, I'm thinking it may be the best non-fiction book I have _ever_ read. I'll sleep on it, and try to come up with a possible competitor.
I am completely stunned.
And whatever you do, don't waste any time or money on Jennifer Estep's _Spider's Bite_.