Thanks to everyone's contributions on defining the concept of co-creation (here and here), I think we're arriving at a pretty good place. Here's where my head's at now:
"An open, ongoing collaboration between employees and customers to define and create products, services, experiences, ideas and information."
Open brings in the idea of transparency, so that non-participants can easily see the collaborative process. This, in my mind, eliminates traditional customer research from the definition.
Ongoing implies that it's not a one-time shot at obtaining customer input and then taking the rest of it in-house. Anyone can participate at any time.
Collaboration brings in the spirit of teamwork. Employees and customers are peers in the process. In many cases, the company simply serves as a facilitator of the process.
Products are probably the most clear-cut application for co-creation: open-source software, Lego Factory, Google's API
Information is probably the next obvious application: epinions.com, Amazon.com, marketingprofs.com forum
Experiences: This gets a bit more fuzzy. A good example is probably Apple iTunes/iPod customized playlists... the company provided the tools to allow customers to create their own music experience. We could get really fuzzy here and say that because a brand is an idea in the minds of customers, then all brands are co-created. But I won't say it, because I think it's confusing the issue. Any more tangible examples of co-created experiences?
Services: This is another tough one. Typically a service company exists to do something that a customer doesn't want to do. Again, would love some ideas on how service companies could work with customers to co-create.
Ideas: What we're doing now. I love co-creating the idea of co-creation!