Now that I'm something of an expert on it, I have Opinions on how to structure a workshop or collaboration event for newbies. Summary of my answer:

• define your goals very clearly and specifically
• skip unnecessary tactics
• choose how to use some mix of speeches, tutorials, sprints, and breathing room

We all want to avoid stultifying slide presentations, and if we preplan the schedule, we might choose irrelevant topics or activities. One alternative is Open Space Technology, which substitutes an alternative, more participatory event structure and nearly guarantees that no one will fire up PowerPoint. Some planners (and participants) think that all planned activities are per se useless, and that thus we should only do unconferences that follow an Open Space model, regardless of the event's audience. More often I run into new event planners who default to "we'll do an unconference" without thinking about whether that's the best tool for the job.

When people suggest removing traditional structure from collaboration events, I think of Mako Hill's research on why Wikipedia succeeded and other contemporaneous projects didn't (summary, audio and video). One reason is: even though the peer production model was unfamiliar and chaotic and new, the goal (an encyclopedia) was well-defined. In contrast, these other projects were trying to redefine both process and THE NATURE OF KNOWLEDGE CYBER COLLAB DISTRIBUTED ETC ETC: both process and outcome.

I think that workshops are kind of like that. You can either be innovative, groundbreaking, and inclusive in what you are doing or how you are doing it, but both, simultaneously, is very hard. (This is also an issue with Agile.)

If you are planning an event for people who already know and trust each other, and are good at public speaking and collaboration, and are experts in the field, then an unconference might work! But for newbies who are learning not just a new skill, but a new way of thinking? Give them a more familiar structure. (WisCon is an interesting example here. It's a massively multiplayer conference: anyone can suggest sessions or suggest themselves as copanelists or moderators. But a programming committee processes that input ahead of time into a great at-con schedule.)

This is tough for free culture ideologues, because one wants to "be the change you wish to see in the world", and do everything collaboratively, empoweredly, etc. But sometimes the ivy needs a trellis to grow on.

I think event organizers should consciously design space in the structure for breathing room. People get a lot out of the breaks, the hallway track, and unconference sessions. But I think it's rare to have a good hallway track without some interesting and structured stuff happening in the rooms just off the hallway.