If God already knows all of our decisions, does this mean we don't have free will?

This was originally part of [this question](https://christianity.stackexchange.com/questions/1478/do-we-have-free-will-or-is-it-an-illusion) However, it's really a separate line of logic (and therefore a different question, imo). If others prefer, I can remerge this into the original. ----- God is omniscient. He truly, literally knows everything. God knows whether or not I will sin. God can (and does) direct certain people to prevent them from choosing one way or another. [Exodus 4:21 (NIV)](http://www.biblegateway.com/passage/?search=Exodus%204:21&version=NIV) >The LORD said to Moses, “When you return to Egypt, see that you perform before Pharaoh all the wonders I have given you the power to do. But I will harden his heart so that he will not let the people go. Clearly, this is an instance where God stepped in and prevent Pharaoh from making the decision. Since he controls decisions and knows what decisions I will make, do I truly have free will? Or do I only have free will in the inconsequential things (which isn't really free will, after all)?