Here are a few of my thoughts on predestination and free will. Beware: This is pretty theoretical, intense stuff and could easily bore you. I just wanted to jot these thoughts down and see if anyone is interested in talking this through, since I'm boring my wife to tears about this by now... ;-)

Naturally, this is all assuming God exists and the Bible is God's revealed truth, etc. etc.

• Our choices are determined or caused by
• Our "being", i.e. who we are
• Our circumstances
• In other words, if someone took a time machine and without influencing anything, watched me make a decision over and over again, it seems logical that I would always make the same decision. Why? Because I would always be the same person, and the circumstances would always be the same.
  
• Put differently: Everything but God has a cause, and this includes any decisions I make with my will - my decisions are caused by who I am, and by the circumstances I am in - both of which themselves have causes.
• If I follow the chain of cause and effect back, it all ends up with God the Creator. God is the one and only Uncaused Cause.
  
• So by creating with omniscience, that is, by creating while knowing the outcome, God thereby predestined.
• Put differently: Omniscience + Omnipotence = Predestination
  
• So what happens with free will? I'd say it depends on your definition of "free"...
• Our will is free from coercion or determination by God: God does not control us or our will like you might control a robot. When I make a decision, it is MY decision alone. I can choose what I want and I alone will be held responsible for my choices. God can and will not be held responsible for the choices I make.
• Our will is not free or independent of our being, of who we are. In other words, I (by definition!) can and will not make choices that are somehow detached from who I am.
• So how can God hold us responsible if He created us? Well, though it's a tough passage, check out Romans 9 with an open mind. I'd summarize Paul's thoughts there by saying that the act of creation itself is never a negative thing - simply because God chooses to create someone though He knows full well how that person will decide does not make it God's responsibility when His creation turns against him.
• God could have "picked and chosen" who He created so that only those people were created who would accept Him. Why didn't He? Good question, I don't know, but I like Piper's take on it which is basically that certain facets of God's character, e.g. His mercy, His wrath, the unconditionality of His love, would never have been able to have been displayed if He had never created "objects of wrath" like it says in Romans 9.
• So all in all: It's really a tough issue, but I think it's funny how I can tend to shy away from the topic mainly because I just don't like the implications, but not because I don't think that thinking about the topic wouldn't reveal more of who God is to me.

I'd LOVE dialog on this topic, please post comments or write me emails on this.

Resources:
Wikipedia article on Free Will
Free Will and Responsibility
Are There Two Wills in God? (John Piper)
Newcomb's Paradox