I am not saying you can’t “pre-plan anything” or be “unorganized”.
* You could have a keynote speaker to open or close your day that is planned ahead. (like the closing of the first day of Mashup Camp 1 had Peter Hirshburg give the BEST speech ever on the history of computer marketing - it was educational and very funny)
* You could know you are going to do a world cafe to close a day about a certain topic.
* You should have some on ramp material with several speakers to open your multi-day event about a technical topic (as we do at the Interenet Identity Workshop).
* You can decide your speed geeking is going to happen after lunch on the 2nd day.
* You can ask everyone who registers what they want to present about or hope to learn about and then post all of that back to potential attendees.