Free will is an illusion of experience arising from a complex neural system which is really just a glorified marble system governed by the laws of ballistic motion. If a super scientist had a map of your brain and knew where all the electrical impulses were located, he could predict exactly what you are going to say, think, and do for the rest of your life. Providing of course that he had you locked in a room where he could control external stimulus, and discounting quantum effects.
Not that it really matters. You're as free as you need to be. It makes no difference if your choices are predetermined as long as you're not technically being "forced" to make one particular choice over another.
http://en.wikipedia.org/wiki/Soft_de...ft_Determinism