Because one IS omnipotent doesn't mean they have to exercise it all the time.
There is the old question about "if God is so powerful can he create a rock so big that he cannot lift it?"
Physcially no, because he transcends the rock.
However, he can limit himself *because* of love - love being his essence, as well as purity and holiness.
If he creates a creature with which he desires to have a free will love relationship, he can limit his direct influence upon that individual for the sake of love - for the sake of himself.
In that way he has created a rock he cannot lift. It is not that he cannot lift it, but that by lifting it, he destroys it.
I guess the modern restatement of this is: Can God create an encryption algorithm that he can't break?
Some have suggested that we have a quantum mechanical / probabilistic world BECAUSE God doesn't want to know what is going to happen so that we can have free will.
However, as others have pointed out, God is outside the whole shebang, so no matter how goofy the laws of physics are, there is no escaping his knowing everything already.
Also, just because we use probabililistic models to make calculations doesn't mean that things actually behave probabalistically. This might just be the closest approximation our limited minds can make.
I'm working on other ideas about the nature of decision making. There were other discussions in the Calvinism/Arminianism debates that suggested that we aren't free because we are bound by sin and human imperfection. I think I have a modest answer to some of these tangents, but none of them involve God deciding not to peek ahead to see whether or not you decide to have Corn Flakes or Oatmeal on July 14, 2005.