In settings, you can un-check all the search options, but there is no way to actually remove the spotlight screen that is to the left of the first homepage
It takes a little getting used to, but you should consider using it.
Instead of flicking through your contacts, just spotlight them. Instead of tapping safari, then tapping the search box, then tapping the "X" to clear out your previous google search, just spotlight it and hit "search web".
If you've got a ton of apps and know the specific app you're going to, spotlight is sometimes faster. Looking for a specific song to play on your ipod is much, much faster than drilling down by album or artist.