To pre-book or not to pre-book, thatis the question.

My wife and I are spending a week in Italy in early July this year. I'm torn between planning and booking all of our hotels and trains ahead of time, or just booking on the fly to allow us to do what we're feeling like doing - if we want to stay an extra day on the Amalfi Coast, or if we're finding Rome too hot and busy and want to move on earlier.

What would you recommend? Are last minute bookings for hotels and trains even possible at that time of year?