Introduction
Simple Foreknowledge is the term used to describe the type of foreknowledge Arminian theologians find in the Bible.  Simple Foreknowledge is not based on God's pre-determining of all events, but on His ability to "see" the future.  He has chosen to give His creatures free-will, but He can see what choices they will make before time begins.  In this view, predestination and election come after God aquires foreknowledge.  Once God looks ahead and sees who will choose Him, He elects those to salvation.  The proof text for this view is usually Rom. 8:28-30.  Here an ordered process of God's working in and with man is presented.  Because foreknew comes before predestined, it is inferred that foreknowledge is the basis of election. 

Some Theological Difficulties
Without answering the question of to what extent man has free will, we can find some problems with Simple Foreknowledge.  [Eph 1:5 says the elect were chosen "according to His good pleasure and will[/v] and Eph. 1:11 says "according to the plan of Him who works out everything in conformity with the purpose of His will." These passages seem to indicate that God chose the elect for reasons other than the content of His foreknowledge.  Whether or not we affirm free will or some compatibility between predestination and free will, we must acknowledge that His election is in some way rooted in His will.  With this in mind, it is very difficult to say that God's foreknowledge can come from His looking into the future at human free-will choices alone.

Some Logical and Philophical Difficulties
Simple Foreknowledge does not provide God with any real ability to "help" in the present.  He may have exhaustive knowledge of everything at every time, but because He already knows what will happen, He is powerless to change it.  The future is already known.  Simple Foreknowledge is then often further defined so as not to include any actions of God.  This way He can still inform His prophets of future events.  But God remains powerless to change the future.  If Billy were to ask God if He should marry Kate or Jennifer, God could only tell Billy what will happen.  If God's foreknowledge says that Billy will marry Kate and the marriage will not work out, this is all God can tell Billy.  God could not tell him to marry Jennifer instead because God already knows what will happen.  This makes prayer not only an empty exercise, but a futile one.

Conclusion
The Simple Foreknowledge view does not adequately explain God's foreknowledge or how He aquires it.  From scripture, we must affirm that God's makes choices about election and predestination based at least partially on His will.  Therefore if foreknowledge is at least somewhat based on man's free-will it must also be based on God's will, which precludes foreknowledge from being simply a snapshot of future human free-will choices.  Also, the future must be at least in some sense under God's control for His foreknowledge of it to be useful.  Otherwise, He is a slave to His own foreknowledge.