Marie Curie, who won two Nobel Prizes -- one for chemistry and one for physics, Albert Einstein, Galileo, Charles Darwin, Thomas Edison and Isaac Newton (listed in no particular order).

Heather,

Besides all of the famous scientists listed by Sallie (all of whom are very inspirational!), my father and mother inspired me. My father was a geologist, so I was exposed to science from a very early age, and my mother always encouraged me to pursue any passion that I had. I was extremely lucky to have such encouraging and successful parents!

Holly

Hi;
When I was in elementary & jr high school, there was an amazing Saturday-science-program at the Boston Museum of Science that had a teacher/lecturer who was simply so engaging, so entertaining, yet so challenging to the kids with his lectures, it inspired me. He showed it could be fun to be a geek. I recall his "gravity" lecture, where he donned a costume, climbed a "Tower of Pisa" (which leaned precariously on cue), and demonstrated various things about gravity. It was hysterical, but also very informative. I just never got bored, and perhaps that in & of itself, was the most influential aspect of the whole thing.