Look up Semco and Ricardo Semler:
Semco has > 3000 people.
If you are curious, try reading this book:
The title is cheesy, but it really is an interesting book, once you get into it. Semler's philosophy is that of questioning things and if no good answers are provided, experiment with changing it.
For instance, he describes how he wanted to let people themselves choose the executive which ended up with him being replaced. :)
Or another experiment where he thought it was silly that the company should dictate the working hours in their factory. He then had to fight the union who thought he was tricking them, until they the finally agreed to a carefully controlled experiment - in the end the workers just held a short meeting the day before and decided among themselves what do to.
Of course, some kind of coordination structure is still needed. But there's a difference between CEO-is-coordinator to CEO-is-tyrant-who-can-fire-you-on-the-spot-if-he-doesn't-like-your-dress.
People will self-organize, and self-organization is powerful because it lets those with the dirty fingers make adjustments that are obvious to them.